Fire protection apparatus, systems and methods for addressing a fire with a mist

ABSTRACT

Fire protection apparatus, systems, and methods for addressing a fire with a mist are provided. More particularly, the invention provides systems and their method of design which provide a water mist to address and preferably suppress a fire. The invention further provides systems and methods for total flooding volume protection of a space to address a fire, preferably control, suppress, and more preferably extinguish a fire. The invention further provides atomizing devices for use in such systems and methods.

PRIORITY DATA AND INCORPORATION BY REFERENCE

This application claims the benefit of priority to (i) U.S. ProvisionalPatent Application No. 60/987,021, filed Nov. 9, 2007; (ii) U.S.Provisional Patent Application No. 60/989,083, filed Nov. 19, 2007; and(iii) U.K. Patent Application No. 0803959.6 filed Mar. 3, 2008, each ofwhich is incorporated by reference in its entirety.

TECHNICAL FIELD

This invention relates generally to liquid mist spray systems andmethods for fire protection. More specifically, the invention isdirected to systems and their method of design which provide a watermist to address and preferably suppress a fire. Even more preferably,the invention relates to systems and methods for total flooding volumeprotection of a space to address a fire, preferably control, suppress,and more preferably extinguish a fire. The invention further providesdevices for use in the systems and methods.

BACKGROUND OF THE INVENTION

Known high pressure water mist systems, such as for example, HI-FOG® byMARIOFF CORPORATION rely on the production of water droplets, rangingbetween 50 μm-120 μm (microns), in which larger droplets entrain smallerdroplets into the critical combustion region of a fire. Providing adesired mix of droplet sizes in the protected area using such as highpressure system requires careful location of the discharge points and alarge quantity of water. The HI-FOG® system is a single fluid (water)system in which the fluid is delivered to the discharging nozzles at ahigh pressure for the 50 μm-120 μm droplet generation.

One type of device for use in such a system is described in WO 92/20453.Shown and described therein is a spray head with a number of nozzlesarranged close to each other for a continuous directional fog spray.

Another water mist system and method is described in U.S. PatentPublication No. 20050000700. Therein is described a fire extinguishingmethod for high spaces such as engine rooms of ships in which a mist isprovided in an unevenly distributed manner so that a circulating motionof the mist is created in the space.

Twin or dual fluid fire protection nozzles are shown and described inU.S. Pat. No. 5,312,041 and U.S. Pat. No. 5,520,331. In U.S. Pat. No.5,312,041, shown and described is a dual fluid method and apparatus forextinguishing fires in which a nozzle discharges a first fluid in a pathsurrounded by a second fluid. In U.S. Pat. No. 5,520,331, shown anddescribed is a convergent/divergent gas nozzle that atomizes a liquidprovided through a liquid delivery tube having an aperture centeredwithin a central gas conduit of an upstream mixing block connected tothe nozzle.

Other water mist systems and nozzles are described in InternationalPatent Application Publication Nos. WO 2003/030995; WO 2005/115555 andInternational Patent Application Publication No. WO 2006/132557 and U.S.Pat. No. 7,080,793. Other Mist generating devices are shown anddescribed in International Patent Publication No. WO 2005/082545 andInternational Patent Publication No. WO 2005/082546, each of which isassigned to Pursuit Dynamics PLC, a named applicant in the instantapplication (outside of the U.S.).

WO 2001/76764 shows a mist generating apparatus which uses two fluids,primarily for use in fire suppression. In WO 2001/76764, a spray offirst fluid droplets is created by forcing the first fluid through anumber of aerosol nozzles in a conventional manner. The droplets arethen carried by a stream of a second fluid through aconvergent-divergent nozzle which sprays the combined stream of firstfluid droplets and second fluid from the apparatus. The purpose of WO2001/76764 is to reduce the pressure required to create the aerosolspray of the first fluid by using the second stream of fluid to carrythe first fluid droplets out of the apparatus. The second stream alsoreduces frictional forces which can in some cases cause the first fluiddroplets forming the aerosol spray to evaporate.

WO 2001/76764 does not use the second fluid in order to create the firstfluid droplet regime. Instead, the droplets are created via an array ofaerosol nozzles which create the droplets in a conventional manner. Thestream of second fluid then carries the droplets through the spraynozzle without any atomization mechanism being applied to the firstfluid by the second fluid. Thus, WO 2001/76764 still requires the firstfluid to be supplied at relatively high pressure in order to create theaerosol droplets.

DISCLOSURE OF INVENTION Installation Methods

One embodiment of the invention is a method of mist fire protection forfixed equipment within a substantially enclosed space having a ceiling,a plurality of walls so as to define a plurality of corners and anenclosure volume of at least 130 cu. m. (4590 cu. ft.). This methodincludes disposing at least one mist generating device in thesubstantially enclosed space, the disposing at least one mist generatingdevice may be selected from (i) mounting at least two mist generatingdevices in the enclosed space, wherein the at least 130 cu. m. (4590 cu.ft.) (4590 cu. ft.) is at least 260 cu. m. (9180 cu. ft), the at leasttwo mist generating devices being disposed in diagonally opposed cornersso as to define a minimum spacing therebetween of about 3.4 m. (11 ft.),(ii) mounting the at least one mist generating device in a pendentconfiguration where the enclosure height ranges between about 3.0 m.(9.8 ft.) to about 8.0 m. (26.2 ft.) with a clearance from any wall ofthe enclosed space ranging from 0.3 m. (1 ft.) to about 3.4 m. (11 ft.),(iii) mounting the at least one mist generating device in a sidewallconfiguration where the enclosure height ranges between about 1.0 m.(3.3 ft.) to about 8.0 m. (26.2 ft.), the mounting being beneath theceiling at a distance from the ceiling ranging from about 1.0 m. (3.3ft.) to about one half the enclosure height and with a clearance of atleast 1.0 m. (3.3 ft.) from any of the plurality of corners of theenclosed space, (iv) mounting at least two mist generating devices in apendent configuration where the enclosure height ranges between about3.0 m. (9.8 ft.) to about 8.0 m. (26.2 ft.) with a clearance from any ofthe plurality of walls of the enclosed space ranging from 0.3 m. (1 ft.)to about 3.4 m. (11 ft.) and spaced from one another by a distanceranging from about 3.4 m. (11 ft.) to about 30.4 ft; and (v) mounting atleast two mist generating devices in a sidewall configuration where thesidewall enclosure height ranges between about 1.0 m. (3.3 ft.) to about8.0 m. (26.2 ft.) beneath the ceiling at a distance from the ceilingranging from about 1.0 m. (3.3 ft.) to about one half the ceilingenclosure height and with a clearance of at least 1.0 m. (3.3 ft.) fromany of the plurality of corners of the enclosed space such that the atleast two mist generating devices each define a center line of dischargehaving an unobstructed discharge path with a diameter of about 1.5 m. (5ft.) from the device to an opposing wall of the plurality of walls, thedevice being mounted from the opposing wall at a distance rangingbetween about 3.8 m. (12.5 ft.) to about 12.0 m. (39.3 ft.) with thecenter lines of discharge of the at least two devices having aperpendicular spacing ranging between about 1.0 m. (3.3 ft.) to about4.6 m. (15 ft.).

The method further includes piping a self-contained fluid supply sourceto the mist generating device. The piping may include coupling an outletof a liquid supply tank having a capacity of at least 25 gallons to themist generating device. The piping may also include coupling in parallela gas supply having a bank of at least three pressurized 11.3 cu. m.(400 cu. ft.) tanks with the liquid supply tank and the mist generatingdevice.

The method further includes interlocking an actuator to release the gasfrom the cylinders to the tank and the at least one mist generatingdevice. The interlocking may include coupling the actuator with a heatrelease detector disposed in the enclosed space, the heat detector beingresponsive to a fire in the enclosed space such that upon detection of afire, the heat detector signals the actuator to release the gas from thecylinders to pressurize the tank and to deliver the gas to the mistgenerating device.

In another embodiment, the invention is a kit to provide mist fireprotection for fixed equipment within a substantially enclosed spacehaving a ceiling, a plurality of walls so as to define a plurality ofcorners and an enclosure volume of at least 130 cu. m. (4590 cu. ft.).The kit comprises at least one mist generating device selected from (i)at least two mist generating devices to be mounted in the enclosedspace, wherein the at least 130 cu. m. (4590 cu. ft.) is at least 260cu. m. (9180 cu. ft.), the at least two mist generating devices to bedisposed in diagonally opposed corners so as to define a minimum spacingtherebetween of about 3.4 m. (11 ft.), (ii) at least one mist generatingdevice to be mounted in a pendent configuration in the enclosed spacewhere the enclosure height ranges between about 3.0 m. (9.8 ft.) toabout 5.0 m. (16.4 ft.) with a clearance from any wall of the enclosedspace ranging from 0.3 m. (1 ft.) to about 3.4 m. (11 ft.), (iii) atleast one mist generating device to be mounted in a sidewallconfiguration in the enclosed space where the enclosure height rangesbetween about 1.0 m. (3.3 ft.) to about 5.0 m. (16.4 ft.), the at leastone mist generating device to be mounted being beneath the ceiling at adistance from the ceiling ranging from about 1.0 m. (3.3 ft.) to aboutone half the enclosure height and with a clearance of at least 1.0 m.(3.3 ft.) from any of the plurality of corners of the enclosed space,(iv) at least two mist generating devices to be mounted in a pendentconfiguration in the enclosed space where the enclosure height rangesbetween about 3.0 m. (9.8 ft.) to about 5.0 m. (16.4 ft.) with aclearance from any of the plurality of walls of the enclosed spaceranging from 0.3 m. (1 ft.) to about 3.4 m. (11 ft.) and spaced from oneanother by a distance ranging from about 3.4 m. (11 ft.) to about 30.4ft; and (v) at least two mist generating devices to be mounted in asidewall configuration in the enclosed space where the sidewallenclosure height ranges between about 1.0 m. (3.3 ft.) to about 5.0 m.(16.4 ft.) beneath the ceiling at a distance from the ceiling rangingfrom about 1.0 m. (3.3 ft.) to about one half the ceiling enclosureheight and with a clearance of at least 1.0 m. (3.3 ft.) from any of theplurality of corners of the enclosed space such that the at least twomist generating devices each define a center line of discharge having anunobstructed discharge path with a diameter of about 1.5 m. (5 ft.) fromthe device to an opposing wall of the plurality of walls, the devicebeing mounted from the opposing wall at a distance ranging between about3.8 m. (12.5 ft.) to about 12.0 m. (39.3 ft.) with the center lines ofdischarge of the at least two devices having a perpendicular spacingranging between about 1.0 m. (3.3 ft.) to about 4.6 m. (15 ft.).

The kit further comprises a self-contained fluid supply source. Theself-contained fluid supply source includes a liquid supply tank havinga capacity of about 25 gallons and a gas supply including a bank of atleast three (3) 11.3 cu. m. (400 cu. ft.) nitrogen gas cylinders coupledto a manifold having an outlet for connection to the at least oneatomizer. The manifold is connected to the liquid supply tank topressurize the tank. The tank includes an outlet for connection to theat least one mist generating device. The kit further includes an orificefor locating in-line between the outlet of the tank and the at least oneatomizer to provide a substantially constant flow of the liquid from thetank to the at least one mist generating device.

Fire Protection Systems

The present invention also provides a mist fire protection system for asubstantially enclosed space of any volume, such as, e.g., a spacehaving a volume of at least one hundred thirty cubic meters (130 cu. m.)or four thousand five hundred and ninety cubic feet (4590 cu. ft),including at least 260 cu. m., such as e.g., 1040 cu. m. The systemincludes at least one mist generating device coupled to a fluid supplysource to deliver to the at least one device, a first fluid and a secondfluid for generation of the mist.

The first fluid is preferably a liquid and is more preferably wateracting as a fire fighting agent. The second fluid is preferably a gasand more preferably an inert gas for both atomizing and entrainment ofthe first fluid for generation and distribution of the mist. Preferably,the liquid and gas are delivered to the device at a sufficient flow rateand pressure for the device to generate a mist to address a fire in theenclosed space. One preferred mist fire protection system generates anddistributes the mist in one of a volume, concentration, and/or densityto address, preferably control or suppress, and more preferablyextinguish a fire.

One exemplary embodiment of this aspect of the present invention is afire protection system for addressing a fire with a mist. This systemincludes at least one mist generating device disposed in an enclosedspace having a volume of at least 130 cu. m. (4590 cu. ft.). The atleast one mist generating device includes (1) a first fluid passagehaving a first fluid inlet and a first fluid outlet disposed about alongitudinal axis of the device, the first fluid passage defining aworking nozzle and a second fluid passage having a second fluid inlet,(2) a second fluid outlet, the second fluid passage disposed about thelongitudinal axis of the device and co-axial with the first fluidpassage, the second fluid passage defining a transport nozzle, (3) asolid protrusion disposed in the second fluid passage so that thetransport nozzle defines a divergent flow pattern with respect to thelongitudinal axis, and (4) a chamber in communication with the workingnozzle and transport nozzle. The system also includes a self-containedfluid supply source including a liquid supply coupled to the first fluidinlet for discharge of liquid from the working nozzle as an annulus. Thefluid supply further includes a gas supply coupled to the second fluidinlet at a pressure ranging from about 2.1 bar (30 psi.) to about 24.1bar (350 psi.) for discharge from the transport nozzle to mix with theliquid annulus in the chamber so as to form the mist to address thefire. The fluid supply has a property selected from the group consistingof: (i) the liquid supply pressurized by the gas supply, the liquidsupply being coupled to the first fluid inlet to provide the liquid tothe inlet at a pressure of at least 0.5 bar (7 psi.) for liquid flowthrough the first fluid passage; (ii) a pressurized gas supply thatincludes a bank of at least three (3) 11.3 cu. m. (400 cu. ft.) nitrogengas cylinders, each cylinder being coupled to a piping manifold coupledto the second fluid outlet with a regulated discharge pressure from themanifold of at least 6.9 bar (100 psi.), and a liquid supply thatincludes at least one ninety-five liter (95 L.) (twenty-five gallon (25gal.)) tank of fire fighting liquid pressurized by the gas supplydischarge pressure, the tank being coupled to the first fluid inlet; and(iii) the liquid and gas being provided to the device in a liquid-to-gasmass flow ratio ranging from about 1:1 to about 3:1.

In this embodiment, the mist further has a property, which is selectedfrom the group consisting of: (i) a majority of droplets having adiameter ranging from 1 to 10 microns, more preferably, substantiallyall of the droplets having a diameter ranging from 1 to 10 microns; (ii)a total liquid supply ranging between about fifty-seven liters (57 L.)(fifteen gallons (15 gal.)) to about ninety-five liters (95 L.)(twenty-five gallons (25 gal.)) for each 130 cu. m. (4590 cu. ft.) ofenclosed space; (iii) defines a total extinguishing volume of less thanabout 8 gallons (8 gal.) for each 130 cu. m. (4590 cu. ft.) of enclosedspace; and (iv) an extinguishment time ranging from about 780 seconds toabout 80 seconds for normalized sized fires ranging between about 1kW/cu. m. to about 8 kW/cu. m.

Another embodiment of this aspect of the invention is a fire protectionsystem for addressing a fire with a mist. This system comprises at leastone mist generating device disposed in an enclosed space having a volumeof at least 130 cu. m. (4590 cu. ft.), the at least one mist generatingdevice including (1) a first fluid passage having a first fluid inletand a first fluid outlet disposed about a longitudinal axis of thedevice, the first fluid passage defining a working nozzle, (2) a secondfluid passage having a second fluid inlet and a second fluid outlet, thesecond fluid passage disposed about the longitudinal axis of the deviceand co-axial with the first fluid passage, the second fluid passagedefining a transport nozzle, (3) a solid protrusion disposed in thesecond fluid passage so that the transport nozzle defines a divergentflow pattern with respect to the longitudinal axis and (4) a chamber incommunication with the working nozzle and transport nozzle

In this embodiment, the at least one mist generating device is mountedwithin the enclosed space in a manner selected from the group consistingof: (i) at least two mist generating devices disposed in the enclosedspace, wherein the at least 130 cu. m. (4590 cu. ft.) is at least 260cu. m. (9180 cu. ft.), the at least two mist generating devices disposedin diagonally opposed corners so as to define a minimum spacingtherebetween of about 3.4 m. (11 ft.); (ii) being mounted in a pendentconfiguration for an enclosure height ranging between about 3.0 m. (9.8ft.) to about 5.0 m. (16.4 ft.) with a clearance from any wall of theenclosed space ranging from 1.2 m. (4 ft.) to about 3.4 m. (11 ft.),(iii) being mounted in a sidewall configuration for a sidewall enclosureheight ranging between about 1.0 m. (3.3 ft.) to about 5.0 m. (16.4 ft.)beneath a ceiling of the enclosed space ranging from about 1.0 m. (3.3ft.) to about one half the ceiling enclosure height and with a clearanceof at least 1.0 m. (3.3 ft.) from any corner of the enclosed space; (iv)at least two mist generating devices mounted in a pendent configurationfor an enclosure height ranging between about 3.0 m. (9.8 ft.) to about5.0 m. (16.4 ft.) with a clearance from any wall of the enclosed spaceranging from 1.2 m. (4 ft.) to about 3.4 m. (11 ft.) and spaced from oneanother by a distance ranging from about 3.4 m. (11 ft.) to about 6.7 m.(22 ft.); and (v) at least two mist generating devices being mounted ina sidewall configuration for a sidewall enclosure height ranging betweenabout 1.0 m. (3.3 ft.) to about 5.0 m. (16.4 ft.) beneath a ceiling ofthe enclosed space ranging from about 1.0 m. (3.3 ft.) to about one halfthe ceiling enclosure height and with a clearance of at least 1.0 m.(3.3 ft.) from any corner of the enclosed space such that the at leasttwo mist generating devices each define a center line of dischargehaving an unobstructed discharge path with a diameter of about 1.5 m. (5ft.) from the device to an opposing wall, the device being mounted fromthe opposing wall at a distance ranging between about 3.8 m. (12.5 ft.)to about 12.0 m. (39.3 ft.) with the center lines of discharge of the atleast two devices having a perpendicular spacing ranging between 1.0 m.(3.3 ft.) to about 4.6 m. (15 ft.).

This system further includes a self-contained fluid supply sourceincluding a liquid supply coupled to the first fluid inlet for dischargeof liquid from the working nozzle as an annulus, the fluid supplyfurther including a gas supply coupled to the second fluid inlet at apressure ranging from about 2.1 bar (30 psi.) to about 24.1 bar (350psi.) for discharge from the transport nozzle to mix with the liquidannulus in the chamber so as to form the mist to address the fire. Thefluid supply further has a property that is selected from the groupconsisting of: (i) the liquid supply pressurized by the gas supply, theliquid supply being coupled to the first fluid inlet to provide theliquid to the inlet at a pressure of at least 0.5 bar (7 psi.) forliquid flow through the first fluid passage, (ii) a pressurized gassupply that includes a bank of at least three (3) 11.3 cu. m. (400 cu.ft.) nitrogen gas cylinders, each cylinder being coupled to a pipingmanifold coupled to the second fluid outlet with a regulated dischargepressure from the manifold of at least 6.9 bar (100 psi.), and a liquidsupply that includes at least one ninety-five liter (95 L.) (twenty-fivegallon (25 gal.)) tank of fire fighting liquid pressurized by the gassupply discharge pressure, the tank being coupled to the first fluidinlet; and (iii) the liquid and gas being provided to the device in aliquid-to-gas mass flow ratio ranging from about 1:1 to about 3:1.

In this system, the mist further has a property that is selected fromthe group consisting of: (i) a majority of droplets having a diameterranging from 1 to 10 microns, (ii) a total liquid supply ranging betweenabout fifty-seven liters (57 L.) (fifteen gallons (15 gal.)) to aboutninety-five liters (95 L.) (twenty-five gallons (25 gal.)) for each 130cu. m. (4590 cu. ft.) of enclosed space, defines a total extinguishingvolume of less than about 8 gallons (8 gal.) for each 130 cu. m. (4590cu. ft.) of enclosed space, and an extinguishment time ranging fromabout 780 seconds to about 80 seconds for a normalized sized firesranging between about (1 kW/cu. m.) to about (8 kW/cu. m.).

Another embodiment of the invention is a fire protection system foraddressing a fire with a mist. This system comprises: at least oneatomizing device disposed in an enclosed space having a volume of atleast 130 cu. m. (4590 cu. ft.), the at least one atomizing deviceincluding: a first fluid passage having a first fluid inlet and a firstfluid outlet disposed about a longitudinal axis of the device, the firstfluid passage defining a smooth curving profile that converges towardthe longitudinal axis such that a flow path decreases in a directionfrom the first fluid inlet to the first fluid outlet, the first fluidpassage defining a total volume ranging between 119,000 cu. mm and121,500 cu. mm., a second fluid passage having a second fluid inlet anda second fluid outlet through which a second fluid passes, the secondfluid passage disposed about the longitudinal axis concentric, orsubstantially concentric, with the first fluid passage, the second fluidpassage defining an equivalent angle of expansion ranging from about 1to about 40 degrees, the second fluid passage defining a total volumeranging between about 24,300 cu. mm. to about 25,500 cu. mm., and achamber in communication with the first and second fluid outlets,wherein the first and second fluid outlets are oriented relative to oneanother such that they have an angle of incidence between about 5degrees and about 30 degrees.

The system further includes a self-contained fluid supply sourceincluding a liquid supply coupled to the first fluid inlet for dischargeof liquid from the first fluid outlet as an annulus. The fluid supplyalso includes a gas supply coupled to the second fluid inlet at apressure ranging from about 2.1 bar (30 psi.) to about 24.1 bar (350psi.) for discharge from the second fluid outlet to mix with the liquidannulus in the chamber so as to form the mist to address the fire. Thefluid supply further has a property that is selected from the groupconsisting of: (i) the liquid supply pressurized by the gas supply, theliquid supply being coupled to the first fluid inlet to provide theliquid to the inlet at a pressure of at least 0.5 bar (7 psi.) forliquid flow through the first fluid passage; (ii) a pressurized gassupply that includes a bank of at least three (3) 11.3 cu. m. (400 cu.ft.) nitrogen gas cylinders, each cylinder being coupled to a pipingmanifold coupled to the second fluid outlet with a regulated dischargepressure from the manifold of at least 6.9 bar (100 psi.), and a liquidsupply that includes at least one ninety-five liter (95 L.) (twenty-fivegallon (25 gal.)) tank of fire fighting liquid pressurized by the gassupply discharge pressure, the tank being coupled to the first fluidinlet; and (iii) the liquid and gas being provided to the device in aliquid-to-gas mass flow ratio ranging from about 1:1 to about 3:1.

In this system, the mist further has a property that is selected fromthe group consisting of: (i) a majority of droplets having a diameterranging from 1 to 10 microns, (ii) a total liquid supply ranging betweenabout fifty-seven liters (57 L.) (fifteen gallons (15 gal.)) to aboutninety-five liters (95 L.) (twenty-five gallons (25 gal.)) for each 130cu. m. (4590 cu. ft.) of enclosed space, (iii) defines a totalextinguishing volume of less than about 8 gallons (8 gal.) for each 130cu. m. (4590 cu. ft.) of enclosed space; and (iv) an extinguishment timeranging from about 780 seconds to about 80 seconds for normalized sizedfire ranging between about 1 kW/cu. m. to about 8 kW/cu. m.

A further embodiment of the invention is a fire protection system foraddressing a fire with a mist. This system comprises: at least oneatomizing device disposed in an enclosed space having a volume of atleast 130 cu. m. (4590 cu. ft.). The at least one atomizing deviceincludes: a first fluid passage having a first fluid inlet and a firstfluid outlet disposed about a longitudinal axis of the device, the firstfluid passage defining a smooth curving profile that converges towardthe longitudinal axis such that a flow path decreases in a directionfrom the first fluid inlet to the first fluid outlet, the first fluidpassage defining a total volume ranging between about 119,000 cu. mm. toabout 121,500 cu. mm., a second fluid passage having a second fluidinlet and a second fluid outlet through which a second fluid passes, thesecond fluid passage disposed about the longitudinal axis concentricwith the first fluid passage, the second fluid passage defining anequivalent angle of expansion ranging from about 1 to about 40 degrees,the second fluid passage defining a total volume ranging between about24,300 cu. mm. to about 25,500 cu. mm., and a chamber in communicationwith the first and second fluid outlets, wherein the first and secondfluid outlets are oriented relative to one another such that they havean angle of incidence between about 5 degrees and about 30 degrees.

In this system, the device may be mounted within the enclosed space in amanner that is selected from the group consisting of: (i) at least twomist generating devices disposed in the enclosed space, wherein the atleast 130 cu. m. (4590 cu. ft.) is at least 260 cu. m. (9180 cu. ft.),the at least two mist generating devices are disposed in diagonallyopposed corners so as to define a minimum spacing therebetween of about3.4 m. (11 ft.), (ii) being mounted in a pendent configuration for anenclosure height ranging between about 3.0 m. (9.8 ft.) to about 5.0 m.(16.4 ft.) with a clearance from any wall of the enclosed space rangingfrom 1.2 m. (4 ft.) to about 3.4 m. (11 ft.), (iii) being mounted in asidewall configuration for a sidewall enclosure height ranging betweenabout 1.0 m. (3.3 ft.) to about 5.0 m. (16.4 ft.) beneath a ceiling ofthe enclosed space ranging from about 1.0 m. (3.3 ft.) to about one halfthe ceiling enclosure height and with a clearance of at least 1.0 m.(3.3 ft.) from any corner of the enclosed space, (iv) at least two mistgenerating devices mounted in a pendent configuration for an enclosureheight ranging between about 3.0 m. (9.8 ft.) to about 5.0 m. (16.4 ft.)with a clearance from any wall of the enclosed space ranging from 1.2 m.(4 ft.) to about 3.4 m. (11 ft.) and spaced from one another by adistance ranging from about 3.4 m. (11 ft.) to about 6.7 m. (22 ft.),and (v) at least two mist generating devices being mounted in a sidewallconfiguration for a sidewall enclosure height ranging between about 1.0m. (3.3 ft.) to about 5.0 m. (16.4 ft.) beneath a ceiling of theenclosed space ranging from about 1.0 m. (3.3 ft.) to about one half theceiling enclosure height and with a clearance of at least 1.0 m. (3.3ft.) from any corner of the enclosed space such that the at least twomist generating devices each define a center line of discharge having anunobstructed discharge path with a diameter of about 1.5 m. (5 ft.) fromthe device to an opposing wall, the device being mounted from theopposing wall at a distance ranging between about 3.8 m. (12.5 ft.) toabout 12.0 m. (39.3 ft.) with the center lines of discharge of the atleast two devices having a perpendicular spacing ranging between 1.0 m.(3.3 ft.) to about 4.6 m. (15 ft.).

This system further includes a self-contained fluid supply source, whichhas a liquid supply coupled to the first fluid inlet for discharge ofliquid from the first fluid outlet as an annulus. The fluid supplyfurther including a gas supply coupled to the second fluid inlet at apressure ranging from about 2.1 bar (30 psi.) to about 24.1 bar (350psi.) for discharge from the second fluid outlet to mix with the liquidannulus in the chamber so as to form the mist to address the fire. Thefluid supply further having a property that is selected from the groupconsisting of: (i) the liquid supply pressurized by the gas supply, theliquid supply being coupled to the first fluid inlet to provide theliquid to the inlet at a pressure of at least 0.5 bar (7 psi.) forliquid flow through the first fluid passage, (ii) a pressurized gassupply that includes a bank of at least three (3) 11.3 cu. m. (400 cu.ft.) nitrogen gas cylinders, each cylinder being coupled to a pipingmanifold coupled to the second fluid outlet with a regulated dischargepressure from the manifold of at least 6.9 bar (100 psi.), and a liquidsupply that includes at least one ninety-five liter (95 L.) (twenty-fivegallon (25 gal.)) tank of fire fighting liquid pressurized by the gassupply discharge pressure, the tank being coupled to the first fluidinlet, and (iii) the liquid and gas being provided to the device in aliquid-to-gas mass flow ratio ranging from about 1:1 to about 3:1.

In this system, the mist has a property selected from the groupconsisting of: (i) a majority of droplets having a diameter ranging from1 to 10 microns, (ii) a total liquid supply ranging between aboutfifty-seven liters (57 L.) (fifteen gallons (15 gal.)) to aboutninety-five liters (95 L.) (twenty-five gallons (25 gal.)) for each 130cu. m. (4590 cu. ft.) of enclosed space, (iii) defines a totalextinguishing volume of less than about 8 gallons (8 gal.) for each 130cu. m. (4590 cu. ft.) of enclosed space; and (iv) an extinguishment timeranging from about 780 seconds to about 80 seconds for normalized sizedfires ranging between about 1 kW/cu. m. to about 8 kW/cu. m.

Another embodiment of the invention is a fire protection system foraddressing a fire with a mist. This system comprises: at least oneatomizing device disposed in an enclosed space having a volume of atleast 130 cu. m. (4590 cu. ft.). The at least one atomizing deviceincludes: a first fluid passage having a first fluid inlet and a firstfluid outlet disposed about a longitudinal axis of the device, the firstfluid passage defining a smooth curving profile that converges towardthe longitudinal axis such that a flow path decreases in a directionfrom the first fluid inlet to the first fluid outlet, the first fluidpassage defining a total volume ranging between about 119,000 cu. mm. toabout 121,500 cu. mm., a second fluid passage having a second fluidinlet and a second fluid outlet through which a second fluid passes, thesecond fluid passage disposed about the longitudinal axis concentricwith the first fluid passage, the second fluid passage defining anequivalent angle of expansion ranging from about 1 to about 40 degrees,the second fluid passage defining a total volume ranging between 24,300cu. mm. to about 25,500 cu. mm., and a self-contained fluid supplysource including a liquid supply coupled to the first fluid inlet fordischarge of liquid from the first fluid outlet as an annulus, the fluidsupply further including a gas supply coupled to the second fluid inletat a pressure ranging from about 2.1 bar (30 psi.) to about 24.1 bar(350 psi.) for discharge from the second fluid outlet to mix with theliquid annulus in an optional chamber as, e.g., disclosed herein, so asto form the mist to address the fire.

In this system, the fluid supply further has a property that is selectedfrom the group consisting of: (i) the liquid supply pressurized by thegas supply, the liquid supply being coupled to the first fluid inlet toprovide the liquid to the inlet at a pressure of at least 0.5 bar (7psi.) for liquid flow through the first fluid passage, (ii) apressurized gas supply that includes a bank of at least three (3) 11.3cu. m. (400 cu. ft.) nitrogen gas cylinders, each cylinder being coupledto a piping manifold coupled to the second fluid outlet with a regulateddischarge pressure from the manifold of at least 6.9 bar (100 psi.), anda liquid supply that includes at least one ninety-five liter (95 L.)(twenty-five gallon (25 gal.)) tank of fire fighting liquid pressurizedby the gas supply discharge pressure, the tank being coupled to thefirst fluid inlet; and (iii) the liquid and gas being provided to thedevice in a liquid-to-gas mass flow ratio ranging from about 1:1 toabout 3:1.

In this system, the mist further has a property that is selected fromthe group consisting of: (i) a majority of droplets having a diameterranging from 1 to 10 microns, (ii) a total liquid supply ranging betweenabout fifty-seven liters (57 L.) (fifteen gallons (15 gal.)) to aboutninety-five liters (95 L.) (twenty-five gallons (25 gal.)) for each 130cu. m. (4590 cu. ft.) of enclosed space, (iii) defines a totalextinguishing volume of less than about 8 gallons (8 gal.) for each 130cu. m. (4590 cu. ft.) of enclosed space; and (iv) an extinguishment timeranging from about 780 seconds to about 80 seconds for normalized sizedfires ranging between about 1 kW/cu. m. to about 8 kW/cu. m.

A further embodiment of the invention is a fire protection system foraddressing a fire with a mist. This system comprises at least oneatomizing device disposed in an enclosed space having a volume of atleast 130 cu. m. (4590 cu. ft.). The at least one atomizing deviceincludes: a first fluid passage having a first fluid inlet and a firstfluid outlet disposed about a longitudinal axis of the device, the firstfluid passage defining a smooth curving profile that converges towardthe longitudinal axis such that a flow path decreases in a directionfrom the first fluid inlet to the first fluid outlet, the first fluidpassage defining a total volume ranging between about 119,000 cu. mm. toabout 121,500 cu. mm. and a second fluid passage having a second fluidinlet and a second fluid outlet through which a second fluid passes, thesecond fluid passage disposed about the longitudinal axis concentricwith the first fluid passage, the second fluid passage defining anequivalent angle of expansion ranging from about 1 to about 40 degrees,the second fluid passage defining a total volume ranging between 24,300cu. mm. to about 25,500 cu. mm.

In this system, the device is mounted within the enclosed space in amanner that is selected from the group consisting of: (i) at least twomist generating devices disposed in the enclosed space, wherein the atleast 130 cu. m. (4590 cu. ft.) is at least 260 cu. m. (9180 cu. ft.),the at least two mist generating devices disposed in diagonally opposedcorners so as to define a minimum spacing therebetween of about 3.4 m.(11 ft.); (ii) being mounted in a pendent configuration for an enclosureheight ranging between about 3.0 m. (9.8 ft.) to about 5.0 m. (16.4 ft.)with a clearance from any wall of the enclosed space ranging from 1.2 m.(4 ft.) to about 3.4 m. (11 ft.), (iii) being mounted in a sidewallconfiguration for a sidewall enclosure height ranging between about 1.0m. (3.3 ft.) to about 5.0 m. (16.4 ft.) beneath a ceiling of theenclosed space ranging from about 1.0 m. (3.3 ft.) to about one half theceiling enclosure height and with a clearance of at least 1.0 m. (3.3ft.) from any corner of the enclosed space, (iv) at least two mistgenerating devices mounted in a pendent configuration for an enclosureheight ranging between about 3.0 m. (9.8 ft.) to about 5.0 m. (16.4 ft.)with a clearance from any wall of the enclosed space ranging from about1.2 m. (4 ft.) to about 3.4 m. (11 ft.) and spaced from one another by adistance ranging from about 3.4 m. (11 ft.) to about 6.7 m. (22 ft.),and (v) at least two mist generating devices being mounted in a sidewallconfiguration for a sidewall enclosure height ranging between about 1.0m. (3.3 ft.) to about 5.0 m. (16.4 ft.) beneath a ceiling of theenclosed space ranging from about 1.0 m. (3.3 ft.) to about one half theceiling enclosure height and with a clearance of at least 1.0 m. (3.3ft.) from any corner of the enclosed space such that the at least twomist generating devices each define a center line of discharge having anunobstructed discharge path with a diameter of about 1.5 m. (5 ft.) fromthe device to an opposing wall, the device being mounted from theopposing wall at a distance ranging between about 3.8 m. (12.5 ft.) toabout 12.0 m. (39.3 ft.) with the center lines of discharge of the atleast two devices having a perpendicular spacing ranging between 1.0 m.(3.3 ft.) to about 4.6 m. (15 ft.).

The system further includes a self-contained fluid supply sourceincluding a liquid supply coupled to the first fluid inlet for dischargeof liquid from the first fluid outlet as an annulus, the fluid supplyfurther including a gas supply coupled to the second fluid inlet at apressure ranging from about 2.1 bar (30 psi.) to about 24.1 bar (350psi.) for discharge from the second fluid outlet to mix with the liquidannulus in an optional chamber as, e.g., disclosed herein, so as to formthe mist to address the fire. The fluid supply further has a propertythat is selected from the group consisting of: (i) the liquid supplypressurized by the gas supply, the liquid supply being coupled to thefirst fluid inlet to provide the liquid to the inlet at a pressure of atleast 0.5 bar (7 psi.) for liquid flow through the first fluid passage;(ii) a pressurized gas supply that includes a bank of at least three (3)11.3 cu. m. (400 cu. ft.) nitrogen gas cylinders, each cylinder beingcoupled to a piping manifold coupled to the second fluid outlet with aregulated discharge pressure from the manifold of at least 6.9 bar (100psi.), and a liquid supply that includes at least one ninety-five liter(95 L.) (twenty-five gallon (25 gal.)) tank of fire fighting liquidpressurized by the gas supply discharge pressure, the tank being coupledto the first fluid inlet; and (iii) the liquid and gas being provided tothe device in a liquid-to-gas mass flow ratio ranging from about 1:1 toabout 3:1.

In this system, the mist further has a property that is selected fromthe group consisting of: (i) a majority of droplets having a diameterranging from 1 to 10 microns, (ii) a total liquid supply ranging betweenabout fifty-seven liters (57 L.) (fifteen gallons (15 gal.)) to aboutninety-five liters (95 L.) (twenty-five gallons (25 gal.)) for each 130cu. m. (4590 cu. ft.) of enclosed space, (iii) defines a totalextinguishing volume of less than about 8 gallons (8 gal.) for each 130cu. m. (4590 cu. ft.) of enclosed space, and (iv) an extinguishment timeranging from about 780 seconds to about 80 seconds for normalized sizedfires ranging between about (1 kW/cu. m.) to about (8 kW/cu. m.).

Another embodiment of the invention is a fire protection system foraddressing a fire with a mist. This system comprises at least oneatomizing device disposed in an enclosed space having a volume of atleast 130 cu. m. (4590 cu. ft.). The at least one atomizing deviceincludes: a first fluid inlet and a second fluid inlet, means foratomizing a first fluid and with a second fluid, and a self-containedfluid supply source including a liquid supply coupled to the first fluidinlet for discharge of liquid from the atomizing device as an annulus,the fluid supply further including a gas supply coupled to the secondfluid inlet at a pressure ranging from about 2.1 bar (30 psi.) to about24.1 bar (350 psi.) for discharge from the atomizing device to mix withthe liquid annulus in the chamber so as to form the mist to address thefire. The fluid supply further having a property that is selected fromthe group consisting of: (i) the liquid supply pressurized by the gassupply, the liquid supply being coupled to the first fluid inlet toprovide the liquid to the inlet at a pressure of at least 0.5 bar (7psi.) for liquid flow through the first fluid passage, (ii) apressurized gas supply that includes a bank of at least three (3) 11.3cu. m. (400 cu. ft.) nitrogen gas cylinders, each cylinder being coupledto a piping manifold coupled to the second fluid outlet with a regulateddischarge pressure from the manifold of at least 6.9 bar (100 psi.), anda liquid supply that includes at least one ninety-five liter (95 L.)(twenty-five gallon (25 gal.)) tank of fire fighting liquid pressurizedby the gas supply discharge pressure, the tank being coupled to thefirst fluid inlet, and (iii) the liquid and gas being provided to thedevice in a liquid-to-gas mass flow ratio ranging from about 1:1 toabout 3:1.

In this system, the mist further has a property that is selected fromthe group consisting of: (i) a majority of droplets having a diameterranging from 1 to 10 microns, (ii) a total liquid supply ranging betweenabout fifty-seven liters (57 L.) (fifteen gallons (15 gal.)) to aboutninety-five liters (95 L.) (twenty-five gallons (25 gal.)) for each 130cu. m. (4590 cu. ft.) of enclosed space, (iii) defines a totalextinguishing volume of less than about 8 gallons (8 gal.) for each 130cu. m. (4590 cu. ft.) of enclosed space; and (iv) an extinguishment timeranging from about 780 seconds to about 80 seconds for normalized sizedfires ranging between about (1 kW/cu. m.) to about (8 kW/cu. m.).

A further embodiment of the invention is a fire protection system foraddressing a fire with a mist. This system comprises at least oneatomizing device disposed in an enclosed space having a volume of atleast 130 cu. m. (4590 cu. ft.). The at least one atomizing deviceincludes: a first fluid inlet and a second fluid inlet and means foratomizing a first fluid and with a second fluid. In this system, theatomizing device is mounted within the enclosed space in a manner thatis selected from the group consisting of: (i) at least two mistgenerating devices disposed in the enclosed space, wherein the at least130 cu. m. (4590 cu. ft.) is at least 260 cu. m. (9180 cu. ft.), the atleast two mist generating devices disposed in diagonally opposed cornersso as to define a minimum spacing therebetween of about 3.4 m. (11 ft.),(ii) being mounted in a pendent configuration for an enclosure heightranging between about 3.0 m. (9.8 ft.) to about 5.0 m. (16.4 ft.) with aclearance from any wall of the enclosed space ranging from 1.2 m. (4ft.) to about 3.4 m. (11 ft.), (iii) being mounted in a sidewallconfiguration for a sidewall enclosure height ranging between about 1.0m. (3.3 ft.) to about 5.0 m. (16.4 ft.) beneath a ceiling of theenclosed space ranging from about 1.0 m. (3.3 ft.) to about one half theceiling enclosure height and with a clearance of at least 1.0 m. (3.3ft.) from any corner of the enclosed space, (iv) at least two mistgenerating devices mounted in a pendent configuration for an enclosureheight ranging between about 3.0 m. (9.8 ft.) to about 5.0 m. (16.4 ft.)with a clearance from any wall of the enclosed space ranging from 1.2 m.(4 ft.) to about 3.4 m. (11 ft.) and spaced from one another by adistance ranging from about 3.4 m. (11 ft.) to about 6.7 m. (22 ft.),and (v) at least two mist generating devices being mounted in a sidewallconfiguration for a sidewall enclosure height ranging between about 1.0m. (3.3 ft.) to about 5.0 m. (16.4 ft.) beneath a ceiling of theenclosed space ranging from about 1.0 m. (3.3 ft.) to about one half theceiling enclosure height and with a clearance of at least 1.0 m. (3.3ft.) from any corner of the enclosed space such that the at least twomist generating devices each define a center line of discharge having anunobstructed discharge path with a diameter of about 1.5 m. (5 ft.) fromthe device to an opposing wall, the device being mounted from theopposing wall at a distance ranging between about 3.8 m. (12.5 ft.) toabout 12.0 m. (39.3 ft.) with the center lines of discharge of the atleast two devices having a perpendicular spacing ranging between 1.0 m.(3.3 ft.) to about 4.6 m. (15 ft.).

This system further includes a self-contained fluid supply sourceincluding a liquid supply coupled to the first fluid inlet for dischargeof liquid from the atomizing device as an annulus, the fluid supplyfurther including a gas supply coupled to the second fluid inlet at apressure ranging from about 2.1 bar (30 psi.) to about 24.1 bar (350psi.) for discharge from the atomizing device to mix with the liquidannulus in an optional chamber as, e.g., disclosed herein, so as to formthe mist to address the fire. The fluid supply further having a propertythat is selected from the group consisting of: (i) the liquid supplypressurized by the gas supply, the liquid supply being coupled to thefirst fluid inlet to provide the liquid to the inlet at a pressure of atleast 0.5 bar (7 psi.) for liquid flow through the first fluid passage,(ii) a pressurized gas supply that includes a bank of at least three (3)11.3 cu. m. (400 cu. ft.) nitrogen gas cylinders, each cylinder beingcoupled to a piping manifold coupled to the second fluid outlet with aregulated discharge pressure from the manifold of at least 6.9 bar (100psi.), and a liquid supply that includes at least one ninety-five liter(95 L.) (twenty-five gallon (25 gal.)) tank of fire fighting liquidpressurized by the gas supply discharge pressure, the tank being coupledto the first fluid inlet, and (iii) the liquid and gas being provided tothe device in a liquid-to-gas mass flow ratio ranging from about 1:1 toabout 3:1.

In this system, the mist further has a property that is selected fromthe group consisting of: (i) a majority of droplets having a diameterranging from 1 to 10 microns, (ii) a total liquid supply ranging betweenabout fifty-seven liters (57 L.) (fifteen gallons (15 gal.)) to aboutninety-five liters (95 L.) (twenty-five gallons (25 gal.)) for each 130cu. m. (4590 cu. ft.) of enclosed space, (iii) defines a totalextinguishing volume of less than about 8 gallons (8 gal.) for each 130cu. m. (4590 cu. ft.) of enclosed space; and (iv) an extinguishment timeranging from about 780 seconds to about 80 seconds for normalized sizedfires ranging between about (1 kW/cu. m.) to about (8 kW/cu. m.).

In another embodiment of this aspect of the invention, there is provideda fire protection system for addressing a fire with a mist, the firehaving a normalized fire size ranging between about (1 kW/cu. m.) toabout (8 kW/cu. m.). This system comprises: an atomizer disposed in anenclosed space having a volume of about 130 cu. m. (4590 cu. ft.). Theatomizer includes: a first fluid passage having a first fluid inlet anda first fluid outlet disposed about a longitudinal axis of theapparatus, the first fluid passage defining a working nozzle, a secondfluid passage having a second fluid inlet and a second fluid outlet, thesecond fluid passage disposed about the longitudinal axis of theapparatus and co-axial with the first fluid passage, the second fluidpassage defining a transport nozzle, a solid protrusion disposed in thesecond fluid passage so that the transport nozzle defines a divergentflow pattern with respect to the longitudinal axis, and a chamber incommunication with the working nozzle and transport nozzle, a fluidsupply source including a liquid supply coupled to the first fluid inletat a flow rate of about 5.7 lpm (1.5 gpm) from the working nozzle, thefluid supply further including a gas supply coupled to the second fluidinlet at a pressure ranging from about 6.9 bar (100 psi) for dischargefrom the transport nozzle to mix with the liquid in the chamber so as toform the mist to extinguish the fire.

In this system, the mist further has a property that is selected fromthe group consisting of: (i) a majority of droplets having a diameterranging from 1 to 10 micron, (ii) a total liquid supply ranging betweenabout fifty-seven liters (57 L.) (fifteen gallons (15 gal.)) to aboutninety-five liters (95 L.) (twenty-five gallons (25 gal.)) for each 130cu. m. (4590 cu. ft.) of enclosed space, (iii) defines a totalextinguishing volume of less than about 8 gallons (8 gal.) for each 130cu. m. (4590 cu. ft.) of enclosed space; and (iv) an extinguishment timeranging from about 780 seconds to about 80 seconds for normalized sizedfires ranging between about (1 kW/cu. m.) to about (8 kW/cu. m.).

A further embodiment of the invention is a water mist fire protectionsystem to extinguish a fire including an exposed, shielded, pool, sprayand/or cascading fire. This system comprises at least one atomizerinstalled for introduction of a water mist volume into an occupancy, theat least one atomizer coupled to a fluid supply and a gas supply, thefluid supply being a water supply and the gas supply being a volume ofnitrogen gas (N₂), wherein the water mist volume generated is defined bythe gas being delivered at a pressure ranging from about 2.1 bar (30psi.) to about 24.1 bar (350 psi).

Moreover, each of the systems disclosed herein is preferably scalable toaddress either an increasing or decreasing enclosure volume. Morespecifically, one preferred system is preferably configured to dischargea volume in relation to the size of the enclosed space to be protected.Thus, in one preferred aspect of this embodiment, the at least oneatomizer is a single atomizer that provides substantially equivalentfire protection compared to two or more of the same atomizer, when thetotal volume discharged in the single atomizer is equivalent to thetotal volume discharged by the two or more atomizers.

Methods of Mist Fire Protection

One embodiment of this aspect of the present invention is a method ofmist fire protection to address a fire in a substantially enclosed spacehaving a volume of at least one hundred thirty cubic meters (130 cu. m.(4590 cu. ft.)), which comprises using at least one atomizing devicedisposed in the space for discharge of a mist into the space, the atleast one atomizing device being a twin fluid atomizing device for afirst fluid and a second fluid that includes a first fluid passage and asecond fluid passage, the first fluid passage having a first fluid inletand a first fluid outlet disposed about a longitudinal axis of thedevice, the first fluid passage defining a smooth curving profile thatconverges toward the longitudinal axis such that a flow path decreasesin a direction from the first fluid inlet to the first fluid outlet, thefirst fluid passage defining a total volume ranging between about119,000 cu. mm. to about 121,500 cu. mm., the second fluid passagehaving a second fluid inlet and a second fluid outlet through which asecond fluid passes, the second fluid passage disposed about thelongitudinal axis concentric with the first fluid passage, the secondfluid passage defining an equivalent angle of expansion ranging fromabout 1 to about 40 degrees, the second fluid passage defining a totalvolume ranging between 24,300 cu. mm. to about 25,500 cu. mm., thesecond fluid passage defining a transport nozzle. This method furtherincludes generating a liquid mist using the at least one atomizingdevice including: delivering a liquid as the first fluid to the firstfluid inlet through the first fluid passage for a discharge of theliquid from the first fluid outlet as an annulus, delivering a gas asthe second fluid of to the second fluid inlet of the device at anoperating pressure ranging between about 2.1 bar (30 psi.) to about 24.1bar (350 psi.). for gas flow through the second fluid passage anddischarge from the second fluid outlet to mix with the liquid annulus soas to form the mist, and distributing the mist throughout the enclosedspace. In this method, the distributing includes discharging the liquidand the gas from the atomizing device for a discharge time of at leastten minutes. The discharging the gas includes discharging the gas at avelocity of at least sonic velocity such that the mist has a propertyselected from the group consisting of: (i) a majority of droplets havinga diameter ranging from 1 to 10 microns, (ii) a total liquid supplyranging between about fifty-seven liters (57 L.) (fifteen gallons (15gal.)) to about ninety-five liters (95 L.) (twenty-five gallons (25gal.)) for each 130 cu. m. (4590 cu. ft.) of enclosed space, (iii)defines a total extinguishing volume of less than about 8 gallons (8gal.) for each 130 cu. m. (4590 cu. ft.) of enclosed space, and (iv) anextinguishment time ranging from about 780 seconds to about 80 secondsfor normalized sized fires ranging between about (1 kW/cu. m.) to about(8 kW/cu. m.).

Another embodiment of this aspect of the present invention is a methodof total flooding mist fire protection for an enclosed space. Thismethod comprises: discharging a volume of mist from at least oneatomizing device into the enclosed space, distributing the volume ofmist so as to define a density for each unit of volumetric space in theroom capable of extinguishing a fire located anywhere in the room, andproviding a self-contained fluid supply source. The self contained fluidsupply source includes: a liquid supply coupled to the at least oneatomizing device for discharge of liquid from the device as an annulus;and a gas supply coupled to the at least one atomizing device at apressure ranging from about 2.1 bar (30 psi.) to about 24.1 bar (350psi.) for discharge from the device to mix with the liquid annulus so asto form the mist. In this method, the providing further being selectedfrom the group consisting of: (i) the liquid supply pressurized by thegas supply, the liquid supply being coupled to the first fluid inlet toprovide the liquid to the inlet at a pressure of at least 0.5 bar (7psi.) for liquid flow through the first fluid passage; (ii) apressurized gas supply that includes a bank of at least three (3) 11.3cu. m. (400 cu. ft.) nitrogen gas cylinders, each cylinder being coupledto a piping manifold coupled to the second fluid outlet with a regulateddischarge pressure from the manifold of at least 6.9 bar (100 psi.), anda liquid supply that includes at least one ninety-five liter (95 L.)(twenty-five gallon (25 gal.)) tank of fire fighting liquid pressurizedby the gas supply discharge pressure, the tank being coupled to thefirst fluid inlet; and (iii) the liquid and gas being provided to thedevice in a liquid-to-gas mass flow ratio ranging from about 1:1 toabout 3:1.

This method may further comprise generating the mist by means of one ofthe parameters selected from the group consisting of: (i) a majority ofdroplets having a diameter ranging from 1 to 10 microns, (ii) a totalliquid supply ranging between about fifty-seven liters (57 L.) (fifteengallons (15 gal.)) to about ninety-five liters (95 L.) (twenty-fivegallons (25 gal.)) for each 130 cu. m. (4590 cu. ft.) of enclosed space,(iii) defines a total extinguishing volume of less than about 8 gallons(8 gal.) for each 130 cu. m. (4590 cu. ft.) of enclosed space, and (iv)an extinguishment time ranging from about 780 seconds to about 80seconds for normalized sized fires ranging between about (1 kW/cu. m.)to about (8 kW/cu. m.).

In this method, the at least one atomizer may comprise: a first fluidpassage having a first fluid inlet and a first fluid outlet disposedabout a longitudinal axis of the apparatus, the first fluid passagedefining a working nozzle, a second fluid passage having a second fluidinlet and a second fluid outlet, the second fluid passage disposed aboutthe longitudinal axis of the apparatus and co-axial with the first fluidpassage, the second fluid passage defining a transport nozzle, a solidprotrusion disposed in the second fluid passage so that the transportnozzle defines a divergent flow pattern with respect to the longitudinalaxis, and a chamber in communication with the working nozzle andtransport nozzle.

This method may further comprise generating liquid droplets forming theliquid mist, wherein a majority of the droplets have a diameter rangingfrom 1 to 5 microns. This method may further comprise generatingturbulence in the volume so as to induce air currents capable oftransporting and dispersing the liquid mist. In this method, the gas maybe discharged at a supersonic speed. In this method, the discharging mayinclude defining a total liquid volume to extinguish a normalized firesize measured in kilowatts per cubic meter (kW/cu. m.), the totalextinguishing volume ranging respectively from about 0.57 liters percubic meter (0.57 liters/cu. m.) (0.0042 gallons per cubic foot (0.0042gal./cu. ft.)) to 0.057 liters per cubic meter (0.057 liters/cu. m.)(0.00042 gallons per cubic foot (0.00042 gal./cu. ft.)) for a normalizedrange of fire sizes ranging from about one (1 kW/m3) to about eight (8kW/m3).

The discharging may be a function of the space being protected, whichmay have a volume of about 260 cubic meter (cu. m.) and the liquid mistmay define an extinguishment volume of about four gallons (4 gal.) ofliquid to about forty gallons (40 gal.).

In this method, discharging a liquid mist extinguishes a fire anddefines a range of extinguishing times ranging respectively from about780 seconds to about 80 seconds for normalized fire sizes rangingbetween about (1 kW/cu. m.) to about (8 kW/cu. m.).

In this method, preferably, discharging a liquid mist extinguishes afire and defines a range of extinguishing times from about 500 secondsto about 80 seconds for normalized fire sizes ranging between about (1kW/cu. m.) to about (8 kW/cu.

In this method, more preferably, discharging a liquid mist extinguishesa fire and defines a range of extinguishing times from about, 420seconds to about 80 seconds for normalized fire sizes ranging betweenabout (1 kW/cu. m.) to about (8 kW/cu. m.).

In another embodiment of this aspect of the invention, a method ofgenerating a mist is provided. This method comprises: passing a firstfluid through a first fluid passage of a mist generating apparatus,wherein the first fluid passage has a first fluid outlet, causing asecond fluid to flow through a second fluid passage of the mistgenerating apparatus, wherein the second fluid passage has a secondfluid outlet and a throat portion, the throat portion having a smallercross sectional area than the second fluid outlet, wherein the first andsecond fluid outlets are oriented relative to one another such that theyhave an angle of incidence between 5 and 30 degrees, accelerating theflow of second fluid through the throat portion of the second fluidpassage, and ejecting the first and second fluids from their respectiveoutlets such that a stream of accelerated second fluid issuing from thesecond fluid outlet imparts a shear force on a stream of first fluidissuing from the first fluid outlet, thereby at least partiallyatomising the first fluid to create a dispersed droplet flow regime.

Another embodiment of this aspect of the invention is a method ofgenerating a mist. This method comprises: passing a first fluid througha first fluid passage of a mist generating apparatus, wherein the firstfluid passage has a first fluid outlet, causing a second fluid to flowthrough a second fluid passage of the mist generating apparatus, whereinthe second fluid passage has a second fluid outlet and a throat portion,the throat portion having a smaller cross sectional area than the secondfluid outlet such that the area ratio between the throat portion and thesecond fluid outlet is between 2:3 and 1:4, wherein the first and secondfluid outlets are oriented relative to one another such that they havean angle of incidence of less than 90 degrees, accelerating the flow ofsecond fluid through the throat portion of the second fluid passage, andejecting the first and second fluids from their respective outlets suchthat a stream of accelerated second fluid issuing from the second fluidoutlet imparts a shear force on a stream of first fluid issuing from thefirst fluid outlet, thereby at least partially atomising the first fluidto create a dispersed droplet flow regime.

The previous two embodiments may further comprise: creating a turbulentregion in the second fluid downstream of the outlets and passing thedispersed droplet flow regime through the turbulent region, therebyfurther atomising the first fluid in the dispersed droplet flow regime.

The methods of the present invention may further comprise the step ofcontrolling the momentum flux ratio between the first and second fluidsby varying the velocity and/or density of the first and/or second fluid.

The methods of present invention may further comprise the step ofadjusting the cross sectional area of the first fluid outlet in order tovary the exit velocity of the first fluid stream. Preferably, the exitvelocity is supersonic.

Assembly Methods

In another embodiment of the present invention, a method of assembling amist generating apparatus is provided. This method comprises the stepsof: forming a base member containing first and second fluid supplychannels, forming a funnel member containing a bore, and axially andconcentrically locating the funnel member on the base member such thatthe bore communicates with the second fluid supply channel, forming anelongate plug member, and axially and concentrically attaching the plugmember to the base member such that a portion of the plug member lieswithin the bore and a second fluid passage is defined between theconcentric funnel and plug members, forming a cover member, the covermember having a first end adapted to enclose the funnel and plugmembers, and adapted to axially and concentrically locate on the basemember, the cover member further comprising a second end having anoutlet, and attaching the cover member to the base member such that afirst fluid passage is defined between an external surface of the funnelmember and an internal surface of the cover member, and a first fluidoutlet of the first fluid passage and the second fluid outletcommunicate with the outlet of the cover member.

In one aspect of this embodiment, the step of forming the funnel mayinclude forming a flange portion projecting radially therefrom, andwherein the step of attaching the cover member to the base includessandwiching the flange portion of the funnel between the cover memberand the base.

In another aspect of this embodiment, the step of attaching the covermember to the base includes adapting the cover member such that theaxial position of the cover member may be adjusted relative to the base.

In a aspect of this embodiment, the step of attaching the plug member tothe base includes threading the plug member onto the base such that theaxial position of the plug may be adjusted relative to the base and thefunnel.

The Atomizing Device

In another embodiment of the present invention, an atomizing device isprovided. This device comprises: a first fluid passage having a firstfluid inlet and a first fluid outlet disposed about a longitudinal axisof the device, the first fluid passage defining a smooth curving profilethat converges toward the longitudinal axis such that a flow pathdecreases in a direction from the first fluid inlet to the first fluidoutlet, the first fluid passage defining a total volume ranging betweenabout 119,000 cu. mm. to about 121,500 cu. mm., a second fluid passagehaving a second fluid inlet and a second fluid outlet through which asecond fluid passes, the second fluid passage disposed about thelongitudinal axis concentric with the first fluid passage, the secondfluid passage defining an equivalent angle of expansion ranging fromabout 1 to about 40 degrees, the second fluid passage defining a totalvolume ranging between 24,300 cu. mm. to about 25,500 cu. mm., thesecond fluid passage defining a transport nozzle, and a chamber incommunication with the first and second fluid outlets, wherein the firstand second fluid outlets are oriented relative to one another such thatthey have an angle of incidence between about 5 degrees and about 30degrees.

In another embodiment of this aspect of the present invention, anatomizing device is provided, which device comprises: a first fluidpassage having a first fluid inlet and a first fluid outlet disposedabout a longitudinal axis of the device, the first fluid passagedefining a smooth curving profile that converges toward the longitudinalaxis such that a flow path decreases in a direction from the first fluidinlet to the first fluid outlet, the first fluid passage defining atotal volume ranging between about 119,000 cu. mm. to about 121,500 cu.mm. and a second fluid passage having a second fluid inlet and a secondfluid outlet through which a second fluid passes, the second fluidpassage disposed about the longitudinal axis concentric with the firstfluid passage, the second fluid passage defining an equivalent angle ofexpansion ranging from about 1 to about 40 degrees, the second fluidpassage defining a total volume ranging between 24,300 cu. mm. to about25,500 cu. mm., the second fluid passage defining a transport nozzle,the second fluid passage being disposed at angle of incidence betweenthe first and second fluid flow paths, the angle of incidence rangingbetween about 5 degrees and about 30 degrees.

In another embodiment of this aspect of the invention, an atomizingdevice for generating a mist from a liquid and a gas is provided. Theatomizing device comprises: a first fluid passage having a first fluidinlet for receipt of the liquid at a flow rate between about 1-4 gpm,such as e.g., between about 3.8 lpm to about 7.61 lpm (1-2 gpm), thefirst fluid passage having a first fluid outlet disposed about alongitudinal axis of the apparatus for discharge from the first fluidpassage as annulus, a second fluid passage having a second fluid inletfor receipt of the gas at a pressure of about 6.9 bar (100 psi.), thesecond fluid passage having a second fluid outlet for discharge of thegas, the second fluid passage isolated from the first passage disposedabout the longitudinal axis of the apparatus and co-axial with the firstfluid passage, a solid protrusion disposed in the second fluid passageso that the second fluid passage defines a divergent flow pattern withrespect to the longitudinal axis. In this embodiment, the liquid and gasare discharged from the first and second fluid outlets so as to form amist, which forms a substantially conical spray pattern. The spraypattern defining an included angle with the longitudinal axis of about15 degrees. Preferably, the device further comprises a chamber incommunication with the first and second fluid outlets for mixture of theliquid and gas discharge so as to form the mist.

In another embodiment of this aspect of the present invention, there isprovided a mist generating apparatus having a longitudinal axis. Thisapparatus comprises: a first fluid passage having a first fluid inletand a first fluid outlet and a second fluid passage having a secondfluid inlet and a second fluid outlet. The first fluid passage surroundsthe second fluid passage, and the first and second fluid outlets areoriented relative to one another such that they have an angle ofincidence between 5 and 30 degrees. The second fluid passage has athroat portion located between the second fluid inlet and the secondfluid outlet, wherein the throat portion has a smaller cross sectionalarea than that of either the second fluid inlet or second fluid outlet.

In this embodiment, preferably the area ratio between the throat portionand the second fluid outlet is between 2:3 and 1:4.

In this embodiment, the first fluid passage may be located radiallyoutward from the second fluid passage.

Preferably, the first and second fluid passages are coaxial with thelongitudinal axis of the apparatus.

In this embodiment, the first fluid passage may comprise an intermediateportion located between the first fluid inlet and the first fluidoutlet, wherein the intermediate portion has a cross sectional areawhich is larger than that of either the first fluid inlet or the firstfluid outlet.

In this embodiment, the apparatus may further comprise: a first fluidsupply channel having a first end adapted to be connected to a supply ofa first fluid and a second end connected to the first fluid inlet and asecond fluid supply channel having a first end adapted to be connectedto a supply of a second fluid and a second end connected to the secondfluid inlet, wherein the first and second supply channels aresubstantially parallel to the longitudinal axis of the apparatus.Preferably, the apparatus further comprises a base member that containsthe first and second fluid supply channels.

The apparatus may further comprise a funnel member and an elongate plugmember, wherein the funnel member has a bore and is adapted to coaxiallylocate upon the base member such that the bore communicates with thesecond fluid supply channel, and wherein the plug member is adapted tobe attached to the base member such that a portion of the plug lieswithin the bore and the second fluid passage is defined between thefunnel and the plug.

The apparatus may further comprise a cover member which encloses thebase member, the funnel member and the plug member such that the firstfluid passage is defined between an outer surface of the funnel and aninner surface of the cover member. Preferably, the cover member has afirst end adapted to coaxially locate upon the base member and beattached thereto, and a second end having an outlet adapted tocommunicate with the first and second fluid outlets. Preferably, thesecond end of the cover includes an axially projecting lip portion, thelip portion defining an aperture in communication with the first andsecond fluid outlets.

In the apparatus, the plug member has a first end which attaches to thebase member and a second end which defines the second fluid passage,wherein the second end has an end face which is concave.

In the apparatus, the funnel member may include a radially projectingflange portion, wherein the flange portion is sandwiched between thebase member and the cover member to maintain the axial position of thefunnel member relative to the base member.

The apparatus may be adapted such that the axial position of the covermember may be adjusted relative to the base.

In the apparatus, the plug member may be threaded onto the base suchthat the axial position of the plug member may be adjusted relative tothe base and the funnel.

In another embodiment of this aspect of the present invention, there isprovided a mist generating apparatus having a longitudinal axis. Theapparatus comprises: a first fluid passage having a first fluid inletand a first fluid outlet and a second fluid passage having a secondfluid inlet and a second fluid outlet. The first fluid passage surroundsthe second fluid passage and the first and second fluid outlets areoriented relative to one another such that they have an angle ofincidence of less than 90 degrees. In this apparatus, the second fluidpassage includes a throat portion located between the second fluid inletand the second fluid outlet, the throat portion having a smaller crosssectional area than that of either the second fluid inlet or secondfluid outlet such that the area ratio between the throat portion and thesecond fluid outlet is between 2:3 and 1:4. The apparatus includes thefirst fluid passage being located radially outward from the second fluidpassage.

In this embodiment, the first and second fluid passages are coaxial withthe longitudinal axis of the apparatus.

In this embodiment, the first fluid passage includes an intermediateportion located between the first fluid inlet and the first fluidoutlet, the intermediate portion having a cross sectional area which islarger than that of either the first fluid inlet or the first fluidoutlet.

The apparatus of this embodiment further comprises: a first fluid supplychannel having a first end adapted to be connected to a supply of afirst fluid and a second end connected to the first fluid inlet and asecond fluid supply channel having a first end adapted to be connectedto a supply of a second fluid and a second end connected to the secondfluid inlet, wherein the first and second supply channels aresubstantially parallel to the longitudinal axis of the apparatus. Inthis embodiment, the apparatus further comprises a base member thatcontains the first and second fluid supply channels.

The apparatus may comprise a funnel member and an elongate plug member,wherein the funnel member has a bore and is adapted to coaxially locateupon the base member such that the bore communicates with the secondfluid supply channel, and wherein the plug member is adapted to beattached to the base member such that a portion of the plug lies withinthe bore and the second fluid passage is defined between the funnel andthe plug.

In this embodiment, the apparatus further comprises a cover member whichencloses the base member, the funnel member and the plug member suchthat the first fluid passage is defined between an outer surface of thefunnel and an inner surface of the cover member. Preferably, the covermember has a first end adapted to coaxially locate upon the base memberand be attached thereto, and a second end having an outlet adapted tocommunicate with the first and second fluid outlets. In the apparatus ofthis embodiment, the second end of the cover includes an axiallyprojecting lip portion, the lip portion defining an aperture incommunication with the first and second fluid outlets.

In this embodiment, the plug member has a first end which attaches tothe base member and a second end which defines the second fluid passage,wherein the second end has an end face which is concave.

In this embodiment, the funnel member includes a radially projectingflange portion, wherein the flange portion is sandwiched between thebase member and the cover member to maintain the axial position of thefunnel member relative to the base member. Preferably, the apparatus isadapted such that the axial position of the cover member may be adjustedrelative to the base. In the apparatus of embodiment, the plug membermay be threaded onto the base such that the axial position of the plugmember may be adjusted relative to the base and the funnel.

Other alternative features of the mist generating apparatus arepossible. For example, the cross sectional area of the throat portionmay be between 20 and 35 mm², and an equivalent angle of expansion ofthe second fluid passage between the throat and the second fluid outletmay be between 5 and 10 degrees. The cross sectional area of the secondfluid outlet may be between 4 and 7 times larger than the crosssectional area of the first fluid outlet. Moreover, the first and secondfluid outlets may be located adjacent one another.

BRIEF DESCRIPTIONS OF THE DRAWINGS

The accompanying drawings, which are incorporated herein and constitutepart of this specification, illustrate exemplary embodiments of theinvention, and, together with the general description given above andthe detailed description given below, serve to explain the features ofthe invention.

FIG. 1 is a schematic illustration of a preferred liquid mist fireprotection system.

FIG. 2 is a schematic illustration of another embodiment of a preferredliquid mist fire protection system.

FIG. 3A is an isometric schematic illustration of an embodiment of thesystem of FIG. 1.

FIG. 3B is an isometric schematic illustration of another embodiment ofthe system of FIG. 1.

FIG. 3C is an isometric schematic illustration of another embodiment ofthe system of FIG. 1.

FIG. 3D is an isometric schematic illustration of yet another embodimentof the system of FIG. 1.

FIG. 4A is an installation schematic for the system of FIG. 3A.

FIG. 4B is an installation schematic for the system of FIG. 3B.

FIGS. 5-7 are respectively elevation, plan and side views of aself-contained fluid supply skid for use in the systems of FIGS. 1 and3A-3D.

FIG. 8 is a schematic illustration of the operation of the systems ofFIGS. 1 and 2.

FIG. 9 is a performance plot comparing preferred systems to knownsystems.

FIG. 10 is another performance plot comparing preferred systems to knownsystems.

FIG. 11 is a cross-sectional view of one embodiment of an atomizerassembly.

FIG. 11A is a detailed view of the atomizer assembly of FIG. 11.

FIG. 12A is another detailed view of the atomizer assembly of FIG. 11.

FIG. 12B is a diagram of the relationship between the passages of theatomizer of FIG. 11.

FIG. 13 is a cross-sectional view of the base of the atomizer of FIG.11.

FIG. 13A is a plan end view of the base of FIG. 13.

FIG. 14 is a cross-sectional view of the funnel of the atomizer of FIG.11.

FIG. 15 is a cross-sectional view of the plug of the atomizer of FIG.11.

FIG. 16 is a cross-sectional view of the cover of the atomizer of FIG.11.

FIG. 17 is a cross-sectional view of an embodiment of another atomizerassembly.

FIG. 17A is a detailed view of the atomizer assembly of FIG. 17.

FIG. 18 is a cross-sectional view of an embodiment of another atomizerassembly.

FIG. 18A is a detailed view of the atomizer assembly of FIG. 18.

FIG. 19 is a cross-sectional view of a fluid passage in the atomizer ofFIG. 11.

FIG. 19A is a detailed view of the fluid passage of FIG. 11.

FIG. 20 is a schematic diagram of a spray pattern from the atomizer ofFIG. 11.

FIG. 21 is an exploded view of the atomizer of FIG. 11 and a protectivecap.

FIG. 22 is a plot showing the cumulative frequency distribution ofdroplet sizes in a spray pattern from the atomizer of FIG. 11.

MODE(S) FOR CARRYING OUT THE INVENTION Preferred Systems

Shown in FIG. 1 is a preferred mist system 100, preferably a liquidmist, for providing total flooding mist fire protection of an enclosedspace 120. More specifically, the mist system 100 provides for dropletsof a fire fighting agent suspended in a gas that is distributedthroughout the enclosed space in a concentration effective to address,preferably control or suppress and more preferably extinguish a fire.The fire fighting agent is preferably a liquid such as, for example,water. Alternatively, the fire fighting agent can be steam or further inthe alternative, the fire fighting agent can be a foam such as, forexample, an aqueous film forming foam (AFFF). The AFFF can be made froma synthetically produced material such as, for example, a liquiddetergent mixed with water.

Examples of an enclosed space 120 for which the mist system 100 issuited includes, but are not limited to: engine rooms, turbo machineryrooms, or any other enclosure requiring fire protection of flammableliquid hazards in machinery spaces, special hazard machinery spaces,and/or combustion turbine enclosures. The enclosed space 120 can becharacterized by various dimensional characteristics such as, forexample, a total free volume V measured in cubic meters (cu. m.) orcubic feet (cu. ft.); or by its linear dimensions meters (m.) or feet(ft.) of length, height and width. The total free volume V is defined asthe volume of the enclosure or room minus the fixed volume, in which thefixed volume is defined by the fixed or permanent equipment or othersolid obstruction located in the enclosure.

The enclosed spaced 120 is preferably sealed off to prevent anyventilated exchange between the interior of the enclosed space and theoutside environment. Alternatively, the maximum total area of allnatural ventilation openings into the space, i.e., doorways, is no morethan 4.0 square meters (sq. m.) (43.1 square feet (sq. ft.)). Further inthe alternative, the maximum area of natural ventilation openings canincrease provided the enclosed space has fire rated closures thatautomatically close upon actuation of the system 100. To the extent theenclosed space has forced ventilation systems, i.e., fans and/ordampers, the forced ventilation systems are preferably configured toshut off upon actuation of the preferred fire protection system 100.

The preferred system 100 includes at least one, and preferably two ormore, devices 130 for generating and discharging a mist into asubstantially enclosed space 120 to be protected which defines anenclosure volume V. The discharging devices 130 are preferably liquidatomizing devices or atomizers. In the liquid mist system 100, each ofthe atomizers 130 is in communication with a liquid source 140 of firefighting fluid, preferably water, and a pressurized gas source 150,preferably nitrogen or some other compressible fluid. The gas source 150preferably serves as an atomizing gas to generate the liquid mist and asa carrier gas for distribution of the liquid droplets forming the liquidmist. The gas source 150 is preferably inert and therefore the gas canfurther serve as an inerting agent, enhancing fire suppressionperformance.

Preferably, the liquid source 140 and the gas source 150 of the system100 form a self-contained assembly such that the system 100 has anindependent source of liquid and gas. In the preferred system 100, theliquid source 140 is preferably a dedicated stand alone tank of firefighting liquid, and the gas source 150 is preferably a bank of inertgas cylinders. The gas source 150 is connected to a feed line which iscoupled to, preferably in parallel, to the tank of water 140 and eachone of the atomizers 130. The gas source 150 pressurizes the liquidsource 140 so that the water can be provided to each atomizer 130 at adesired working pressure. The separate gas feed to the atomizers 130provides the gas with which to atomize and entrain the liquid for mistgeneration. The gas discharge from the atomizers further provide for thehigh velocity, preferably sonic to supersonic velocity gas to transportand distribute the mist throughout the enclosure volume V. The liquidsource 140 and gas source 150 are preferably sized to provide for adischarge duration from the atomizers of at least about ten minutes,although the system 100 can be configured for total discharge of theavailable liquid and gas supplies in a time that is either greater orless than ten minutes.

Shown in FIG. 2 is an alternate embodiment 200 of the preferred mistsystem. Instead of utilizing self-contained liquid and gas supplies, thesystem 200 uses available water and gas supplies of the facility beingprotected. For example, the system 200 and each of its atomizers 230 canbe connected, via a manifold 252, to the main water supply 240 and thegas supply 250 of the facility, such as a plant, being protected by thepreferred system.

Referring again to FIG. 1, the preferred system 100 provides, within theenclosed space 120, one or more detectors 160 capable of detecting thepresence of a fire 110 in the enclosed space 120. The detectors 160 (260in FIG. 2) are further preferably coupled to a pneumatic actuator 180 toprovide automatic operation of the system 100. The detectors are furtherpreferably configured to generate a signal to operate the pneumaticactuator 180. The detectors 160 are further preferably coupled to alarmpanel 170 (270 in FIG. 2) to alert system operators for manual operationof the system. The detectors 160 can be configured as any one of a heatdetector, infrared detector, fixed temperature detector, rate oftemperature rise detector, smoke detector, chemical vapor detector,optical detector or a combination thereof. The detectors provide thesystem 100 redundancy or a double interlock configuration to preventfalse trips of the system 100. In operation, the heat detectors 160 arepreferably configured to generate a signal to trip an alarm signal atthe panel 170 in order to provide audible and/or visual alarm signalsthat a fire 110 has been detected in the space 120.

The operation of the actuator 180 preferably initiates a discharge ofgas from the gas source 150. The discharged gas pressurizes the liquidsource 140 for delivery of the liquid fire fighting agent to each of theatomizers 130 at a desired working pressure or a preferred flow rate. Inthe preferred system 100, an in-line orifice 132 is disposed between theliquid source 140 and each of the atomizers 130 to provide the liquid tothe atomizers 130 at a substantially constant flow rate andsubstantially constant operating pressure. Each of the atomizers 130atomizes the incoming liquid to generate the liquid mist for dischargeinto the space 120 to address a fire 110. The gas is also delivereddirectly to the atomizer 130 to atomize the incoming fluid and fordischarge as a high velocity jet stream. The liquid mist and gas isdischarged with sufficient momentum to dislodge a protective capdisposed about the outlet of the atomizer. The protective cap 1002,shown for example in FIG. 21 (along with a preferred embodiment of anatomizer 1000), covers the outlet of the atomizer to protect theinternals of the atomizer in its non-actuated state from any debris orcontaminants that may be in the enclosed space 120. The gas ispreferably discharged at a sonic to supersonic velocity, capable ofcreating turbulence within the enclosed space 120 and/or inducing lowvelocity currents that can transport and distribute the liquid mistthroughout the enclosed space 120 to provide for preferred liquid misttotal flooding fire protection.

The liquid mist is preferably composed of a large quantity of liquiddroplets ranging in size from about 1 micron to about 10 microns andmore preferably 1 to about 5 microns that are capable of beingtransported by the induced air currents. The discharged liquid dropletsare dispersed throughout the enclosed space 120 so as to surround thefire 110. The droplets engage the fire, evaporate and generate a largevolume of steam or liquid vapor capable of displacing oxygen. The rateof discharge of liquid mist and its density or concentration throughoutthe space is such that the rate of evaporation can effectively displacethe oxygen so as to address the fire, preferably control or suppress thefire, and even more preferably extinguish the fire. In addition todisplacing oxygen, the liquid vapor dilutes flammable vapors by theentrainment of the liquid vapor. As the liquid is converted to vapor,heat is extracted from the fire to cool the fuel.

Further preferred embodiments of a liquid mist fire protection systemwith a self-contained fluid supply are shown schematically in FIGS.3A-D, 4A and 4B and described in TYCO FIRE & BUILDING PRODUCTS draftData Sheet TFP2280 entitled, “Aquasonic™: Total Flooding Water Mist Type130 and 260 Systems” (Draft-November, 2007), which is attached to U.S.Provisional Patent Application No. 60/989,083 and incorporated byreference in its entirety. The system 300′ of FIG. 3A is preferablyconfigured with two atomizers 330′ pendent mounted for protection of asubstantially enclosed space defining a free volume up to 260 cubicmeters (cu. m.) (9180 cu. ft.). The system 300″ of FIG. 3B is preferablyconfigured with two atomizers 330″ sidewall mounted for protection of asubstantially enclosed space defining a free volume up to 260 cubicmeters (cu. m.) (9180 cu. ft.). The system 400′ of FIG. 3C is preferablyconfigured with a single atomizer 430′ that is pendent mounted forprotection of a substantially enclosed space defining a free volume upto 130 cubic meters (cu. m.) (4590 cu. ft.). The system 400″ of FIG. 3Dis preferably configured with a single atomizer 430″ sidewall mountedfor protection of an area up to 130 cubic meters (cu. m.) (4590 cu.ft.). For the pendent mounted systems 300′, 400′, fire protection ispreferably provided to the enclosed space 120 in which the enclosureheight can vary from about 3.0 meters to about 5.0 meters (about 9.8 ft.to about 16.4 ft.) up to about 8.0 meters (26.2 ft.). For the sidewallsystems 300″, 400″, fire protection is preferably provided to theenclosed space 120 in which the enclosure height can vary from about 1.0meter to about 3.0 meters to more preferably about 5.0 meter (about 3.3to about 16.4 ft.) up to about 8.0 meters (26.2 ft.).

Although, testing of the preferred mist systems has demonstrated theability to provide fire protection independent of the atomizer locationwithin the enclosed space 120. The inventors have identified preferredlocations for atomizer installation within the enclosed space 120. Inthe pendent systems 300′, 400′, the atomizers are preferably located ata minimum of about 1.2 m. (4 ft.), preferably a minimum of 0.3 m. (1ft.) and a maximum 3.4 m. (11 ft.) from any enclosure wall such that theatomizer has an unobstructed discharge path of about 1.2 m. (4 ft. andmore preferably 0.9 m. (3 ft.) in diameter from the atomizer to thefloor of the enclosure. In the case of the dual pendent atomizer system300′ the atomizers are preferably located on opposite adjacent quadrantsor corner areas of the enclosure 20′ as shown, for example, in the planinstallation schematic of FIG. 4A disposed about the fixed equipment127. More preferably, the two atomizers 330 have a space D in betweentheir centers of about 3.4 meters (11 ft.) and no greater than about 9.3meters (30.4 ft).

A preferred installation for the sidewall mounted systems 300″, 400″provide that the atomizers are preferably mounted on the shorter widthwalls of the enclosed space 120 where the enclosure space has arectangular floor plan. The atomizers of the preferred sidewall systemsare mounted at a minimum of about 1.0 meter (3.3 ft.) from any enclosurecorner, and further at a minimum of 3.8 meters (12.5 ft.) to a maximum12.0 meters (39.3 ft) from the opposing enclosure wall. Moreover, theatomizers 430′ are preferably mounted at a minimum of about 1.0 meter(3.3 ft.) below the ceiling to no greater than half the enclosure heightfrom the ceiling with an unobstructed discharge path of about 1.5 meters(4.9 ft.) diameter from atomizer to opposing enclosure wall.

Alternatively or in addition to, where a system installation cannotavoid an obstruction in the discharge path in either the pendent orsidewall configuration, the atomizers are preferably located such thatthe cross-sectional area of a discharged spray pattern contains no morethan a 40% obstruction in the spray pattern development zone, and nomore than 50% obstruction beyond the spray pattern development zone. Thespray pattern development zone is defined as the region from the outletend of the atomizer to a distance DZ distal of the atomizer where thespray pattern is fully developed. In the schematic of the preferredatomizer 1000 shown in FIG. 20, the spray pattern is considered fullydeveloped about 64 inches from the outlet end of the atomizer at whichpoint the spray pattern defines a circular cross-section having adiameter D1A of about 36 inches.

In the case of the dual sidewall atomizer system 300″, the atomizers330′ are preferably located on opposite adjacent quadrants or cornerareas of the enclosure 20′ as shown, for example, in the planinstallation schematic of FIG. 4B. More preferably, the two atomizers330′ should have a space in between so as to define a perpendiculardistance Dp between the atomizers' centerlines CL of discharge rangingbetween a minimum of about 1.0 meters (3 ft-3 in.) to a maximum of about4.6 meters (15 ft-1 in.).

Preferred Piping Installation of the Water Mist Systems

Each of the atomizers in a preferred liquid mist system is preferablycoupled to the fluid supply to ensure that the liquid is delivered tothe atomizers at a preferred substantially constant flow rate and thegas is delivered to the atomizers at a desired operating pressure. Amore preferred installation of a mist fire protection system having twoatomizers for the protection of a 260 cubic meter space (9180 cu. ft.)with a self-contained fluid supply of gas and nitrogen gas is describedin ANSUL INC. publication, Ansul Part No. 435650, entitled “Aquasonic™Water-Atomizing Fire Suppression System: Design, Installation, Rechargeand Maintenance Manual” (2008), which is incorporated by reference inits entirety. The preferred installation provides for a system inconformance with the requirements of the NATIONAL FIRE PROTECTIONASSOCIATION published standard, “NFPA 750: Standard on Water Mist FireProtection Systems” (May 2006). The preferred system is installed so asto provide automatic, manual and optional remote operation. As aself-contained system, the preferred installation provides for aportable skid mount for the liquid supply, gas supply and associatedsystem controls. The skid is preferably configured for outdoor or indoormounting, wherein particular, the skid defines a fluid supply andcontrol assembly having a foot print or overall dimension such that theassembly can be moved through standard size doorways.

Shown at FIGS. 5-7 is a preferred self-contained fluid supply skid 500for use in any one of the above described fluid mist systems. Thepreferred supply skid 500 includes a liquid source configured as a tank502 having with a capacity of at least 95 liters (25 gallons) and morepreferably capacity of about 191 liters (50 gallons) containing a firefighting liquid, preferably water, for protection of at least a 130 cu.m. (4590 cu. ft.) enclosed space, and more preferably a 260 cu. m. (9180cu. ft.) enclosed space. The tank 502 may be alternatively sized toprovide a water supply based on the volume of the protected enclosure;however the tank should be sufficiently sized to provide for a mistdischarge duration of at least ten minutes. The tank 502 is a pressurevessel, preferably ASME certified, to at least about 14.8 bar (215psi.). The tank 502 further includes a fill inlet 506 and an outlet 508for connection to system piping in communication with one or moreatomizers.

The supply skid 500 further includes a gas source 510 that is preferablyconfigured as a bank of cylinders of a substantially inert gas, forexample, nitrogen gas. In the supply skid 500 shown, the bank ofcylinders includes a total of six 11.3 cu. m. (400 cu. ft.) nitrogen gascylinders staged for the protection of the 260 cu. m. (9180 cu. ft.)enclosed space. More or fewer cylinders may be provided depending uponthe size of the space being protected, for example, the supply skid forprotection of the 130 cu. m. (4590 cu. ft.) enclosed space includes atotal of three 11.3 cu. m. (400 cu. ft.) cylinders. Regardless of thenumber or size of cylinders, the gas supply is preferably selected toprovide a mist discharge duration of at least 10 minutes.

The tank 502 and cylinders 510 are housed within a skid supply frame 522that is sized so that the entire skid assembly can fit through astandard size doorway. For the preferred skid assembly 502 shown, theskid has a maximum height H of about 22 m. (6.5 ft.) a maximum width Wof about 0.9 m. (3 ft.) and a maximum length L of about 1.6 m. (5.3 ft.)

In a preferred piping arrangement for any one of the above describedself-contained water mist systems, the gas supply 510 pressurizes theliquid supply 502 such that the liquid and gas are delivered to theatomizer at the same operating pressure, preferably ranging betweenabout 2.1 bar to 24.1 bar (30 psi. to 350 psi.), such as e.g., about 8.3bar (120 psi.) to about 6.9 bar (100 psi.), between about 7.9 bar (115psi.) and about 6.9 bar (100 psi.), between about 7.7 bar (112 psi) andabout 6.9 bar (100 psi.), between about 7.6 bar (110 psi.) and about 6.9bar (100 psi.), and is more preferably about 6.9 bar (100 psi.) Morespecifically, each of the gas cylinders 510 of the skid 500 ispreferably equipped with a gas regulator 512 preferably set to a flowingpressure range between about 7.7 bar (112 psi.). to about 8.3 bar (120psi.) for a pressurized gas feed into a piping manifold 514. The pipingmanifold 514 includes one discharge outlet end 516 to supply the gas tothe atomizers of the system with a preferred minimum pressure of about7.6 bar (110 psi).

The manifold 514 further preferably includes a branched discharge outletend 513 for coupling to the water tank 502 to pressurize the tank 502 ofwater or other liquid supply to a discharge pressure at the water feedoutlet 508 of at least about 7.6 bar (110 psi.). Given the preferredsize of the liquid and gas supplies in the preferred self-containedfluid supply skid 500, the piping between the feed outlet and each ofthe atomizers is sized so as to have a maximum piping volume of no morethan about 50 liters (13 gal.) using pipe ranging from 15 mm. (½ inch)to 25 mm. (1 inch) pipe in diameter. Referring back to the systemschematic of FIG. 1, the water supply piping further preferably includesan in-line orifice device 132 proximate the inlet of each atomizer inletto step down the fluid pressure to the atomizer to a preferablysubstantially constant pressure of about 0.5 bar (7 psi.) and a morepreferred flow rate of about 5.7 lpm (1.5 gpm). The preferred in-linerestriction orifice has a restriction orifice diameter preferablyranging from about 0.080 inches to about 0.092 inches with a coefficientof flow efficiency (Cd) of approximately 0.78. Alternatively or inaddition to, the in-line orifice defines a range of K-factors rangingfrom about 2.13 lpm./(bar)^(1/2) (0.148 gpm./(psi)^(1/2)) to about 2.13lpm./(bar)^(1/2) (0.196 gpm./(psi)^(1/2)), wherein the total flow fromthe atomizer and orifice assembly is equal to the K-factor multiplied bythe square root of the water supply pressure. Accordingly, the gasregulator and the liquid orifice facilitate a constant preferred liquidto gas mass flow ratio in each of the atomizers.

The liquid mist systems preferably provide for manual, automatic and/orremote actuation of the system. Accordingly, as seen in FIG. 5, thesupply skid 500 preferably includes a control panel 515 thatautomatically actuates the liquid mist system after receiving an inputsignal from one or more initiating devices, i.e., a manual actuator orone of the detectors 160. The control panel 515 further preferablyprovides for manual actuation of the system with a manual operatingswitch that can be operated locally or remotely.

A preferred method of operation for each of the preferred water mistsystems is shown in the schematic illustration of FIG. 8. The preferredmethod provides generating a liquid mist to effectively do at least oneof address, control, suppress or more preferably extinguish a fire 110in the enclosed area to be protected. In addition, the preferred methodincludes distributing the mist throughout the enclosed space 120 toeffectively do at least one of address, control, suppress or morepreferably extinguish a fire 110 in the enclosed area to be protected.The distribution of the liquid mist throughout the enclosed space 120preferably provides total flooding of the mist within the enclosedspaces so as to substantially distribute the mist evenly orhomogeneously throughout the enclosed space such that each unit volumeof the enclosed space contains at least an amount or concentration ofmist to effectively address the fire 110 regardless of the location ororientation of the mist generating device relative to the fire.

Distributing the liquid mist further preferably includes generatingturbulence in the enclosed space so as to induce currents capable oftransporting and dispersing the liquid mist. Preferably, the atomizersof the system discharge a gas in the enclosed space 120 at a highvelocity ranging from sonic to a more preferably supersonic speed so asto provide for the preferred turbulence.

Generating the liquid mist preferably defines an average volume or massof mist for each unit of volume of space (mist density), or at leasteach 130 cu. m. (4590 cu. ft.) of enclosure volume V in the enclosedspace 120 that is capable of addressing a fire 110 located anywhere inthe enclosed space 120 via total flooding. Accordingly, the preferredmethod can adequately address a fire 110 that is either shielded orobstructed by an object from the atomizer 130 or alternatively address afire located outside the direct discharge path of the atomizer 130.Thus, the preferred method provides fire protection throughoutsubstantially the entire enclosed space 120, independent of the locationof the atomizer 130 relative to the fire. Moreover because the minimumamount of mist sufficient to address a fire is a function of theenclosure volume V of the enclosed space 120, the method of mistprotection is independent of any particular linear dimensionalcharacteristic of the enclosed space 120.

In addition, the minimum mist density may be a function of the manner inwhich a fire is to be addressed. For example, the preferred method canprovide for a mist density configured to address a fire by any one of:control, suppression and/or extinguishment of a fire. More specifically,the preferred system and its method of generating a liquid mist thatincludes providing an appropriate distribution of droplets having adroplet size effective to address a fire. Preferably, the liquid mist issubstantially composed of liquid droplets having a diameter under 50microns, more preferably under 10 microns and even more preferablyranging from about 1 to about 5 microns. The small water droplet sizemakes it possible for low velocity air currents, stemming from thepreferably generated turbulence, to transport and evenly distributethese droplets in multiple directions within the enclosed space 120.

It is believed that generating a liquid mist having liquid droplets inthe preferred size range in combination with homogeneous distribution ofthe liquid mist throughout the enclosed space 120 can effectivelyaddress a fire independent of the location or orientation of theatomizer 130 by taking advantage of the evaporative capability of theliquid, for example water, to displace oxygen so as to starve a fire ofoxygen in order to address, control, suppress or more preferablyextinguish it. The oxygen displacement by water vapor occurs bothlocally, i.e., within the flame of the fire, and globally, i.e., outsidethe flame and within the enclosed space 120. Moreover the conversion ofthe water to vapor provides for the other fire fighting mechanismdescribed above, for example, extracting heat from the fire cooling thefuel.

Water displaces oxygen by its evaporation, conversion and expansion fromliquid to vapor. A liter of liquid water at atmospheric pressure expandsto approximately 1600-1700 liters of water vapor upon evaporation.Accordingly, the displacement capability of liquid mist for a unitvolume of liquid mist is directly related to the proportion of itsvolume capable of evaporation upon engagement with a fire or the heatemanating therefrom. Thus, the preferred mist systems and their methodof operation deliver into the enclosed space 120 a discharge of mist inwhich a large proportion of the mist is capable of evaporation in aregion proximate the fire plume. Typical fire plumes to be addressed bythe preferred systems, range in velocity from about 1.5 meters persecond (5 ft. per second) to about 15 meters per second (50 ft. persec), and the region in which water droplets of a water mist need toevaporate is within the initial 8 cm. to 30 cm. (3 to 12 inches) of thefire plume.

Not wishing to be limited by any particular theory, it is believed thatwater droplets within this region need to evaporate preferably within arange of 0.02 seconds to about 0.05 seconds to directly extinguish thefire through substantially localized oxygen depletion. By having a watermist in which a large distribution of the water droplets have a size inthe preferred droplet size range of under 10 microns, the mist containsa distribution of droplets that can be evaporated within the 0.02 to0.05 second range upon being within the initial 8 cm. to 30 cm. (3 to 12inches) of the fire plume.

Moreover, because a greater portion of the discharge mist is used foroxygen depletion, a lesser amount of liquid is required to effectivelyaddress a fire as compared to conventional sprinkler systems. Thepreferred method of liquid mist fire protection, or more specificallytotal flooding, is believed to also use less water than known water mistfire protection systems to effectively address a fire. The preferredmethod and its discharged liquid mist includes additional mechanismswith which to address a fire growth, for example, in addition todisplacing oxygen, the evaporation of the water droplets extracts heatfrom the fire thereby cooling the fuel.

The preferred mist systems and methods present an environmentallyfriendly or “green technology” for fire protection. Specifically, thelow volumes of water used by the systems minimizes the water waste andrunoff. In addition, the use of the preferred nitrogen gas as anatomizing and transport fluid does not present an additional hazard tothe environment, system operators or personnel in the event of a fireand system actuation.

System Parameters

The design and performance of the preferred liquid mist systems as awhole can be defined as a function of one or more system inputparameters such as, for example, the pressure and/or flow rate of thefluids to the atomizing devices, the volume and configuration of theenclosed space 120 to be protected, the fuel in the enclosed space to beprotected, the anticipated fire type/size to be addressed by the system,and/or the size and configuration of ventilation opening in the enclosedspace.

More specifically, the volume, flow, mist density, and/or droplet sizeof the fluid mist to be discharged by the system into the enclosed space120 can be defined by, e.g., the inlet characteristics of the gas, theflow rate of liquid and/or the relation between the two. For example, inthe mist fire protection systems described above, a given flow rate ofliquid can provide for a liquid mist effective for addressing a fireprovided there is a sufficient flow and pressure of atomizing gas. Theatomizers 130 used in the preferred methods and systems described aboveare preferably configured as multi-fluid atomizers, for example such as,twin or dual fluid atomizers which preferably use a liquid and a gas forgenerating the mist. Preferred atomizers for use in the above preferredsystems and methods are described in greater detail below.Alternatively, single fluid or other liquid atomizers may be usedprovided such devices can provide for the desired mist havingappropriate volume concentration, droplet size and distributioncharacteristics as described herein.

Described herein below, for example, with respect to using the preferredatomizer of FIG. 11. Applicants have identified an inlet gas pressure orgas operating pressure for formation of the preferred liquid mist thatranges from about 2.1 bar to 24.1 bar (30 psi to 350 psi); preferablyranges from about 5.0 bar to 13.8 bar (72 psi. to about 200 psi); morepreferably ranges from about 5.9 bar to 9.0 bar (85 psi. to about 130psi.); yet even more preferably ranges from about 6.9 bar to about 8.4bar (100 psi. to about 122 psi.); and is most preferably about 7.6 bar(110 psi). Alternatively or in addition to, these inlet gas pressuresdefine mass flow rates and volumetric gas flow rates that preferablyrange from about 0.0141 kg/s (25 scfm) to about 0.1667 kg/s; 0.0476 kg/s(84 scfm) to about 0.0619 kg/s (109 scfm) and is preferably about 0.0476kg/s (84 scfm). The preferred water mist systems and their operation arealso more efficient than known water mist systems because the preferredsystems 300′, 400′ operate at lower pressures than the known highpressure water mist systems. Specifically, known high pressure watermist systems require minimum operating pressure of about 70 bar (1015psi.). Comparatively, the systems 300, 400 only require a minimumoperating pressure of about 6.9 bar (100 psi.).

Applicants have determined that in order to generate a fluid misteffective to address a fire growth using the preferred atomizers, anappropriately configured supply of liquid at the atomizer inlet in viewof the inlet supply of gas is required. Preferably, the liquid pressureat the liquid inlet of the preferred atomizer is about 0.5 bar (7 psi.)and at a flow rate of about 1-4 gpm, such as e.g., about 3 gpm or about3.8 lpm to about 7.61 lpm (1-2 gpm). More preferably, the performance ofa preferred water mist system and the characteristics of the fluid mistto be discharged are a function of the mass flow ratio of liquid to gas.More specifically, the applicants have determined that the preferredatomizers 130 provide an effective liquid mist where the fluids at theinlet of the atomizer 130 provide a liquid to gas mass flow ratio withinthe range of about 1:1 to about 3:1, and more preferably from about1.75:1 to about 2.25:1 to about 2.5:1 for a given inlet mass flow orpressure of gas to the atomizing device. Because such a ratio can bedefined by one fluid as a function of the other, the atomizerperformance and therefore the fire fighting performance of the systemcan be determined by the inlet characteristics of at least one fluid,preferably the gas.

Alternatively, system design and performance can be a function of roomsize. For example, one preferred embodiment of the mist system providesfor discharging at least one of a minimum and maximum volume of liquidmist, measured in liters (L) (gallons (gal.)), to address a fire in theenclosed space 120. In one particular embodiment of the preferred mistsystem a volume of liquid mist discharge ranges from a minimum of about22.7 liters (6 gal.) of liquid to about 57 liters (15 gal.) for fireprotection of an enclosed space 120 having a volume of about 260 cu. m.(9180 cu. ft.). The method further defines for fire protection of anenclosed space 120 having a volume of about 130 cubic meter (cu. m.)(4590 cu. ft.) with a volume of liquid mist discharge ranging from aminimum of 11.4 liters (3 gal.) of liquid to about 28.4 liters (7.5gal.) for the same concentration of droplets. In one preferred aspect, atotal liquid supply volume of a preferred system preferably ranges fromfifty-seven liters (57 L.) (fifteen gallons (15 gal.)) to aboutninety-five liters (95 L.) (twenty-five gallons (25 gal.)) for each 130cu. m. (4590 cu. ft.) of enclosed space.

Although the preferred mist systems are sized for a minimum totaldischarge time, preferably about ten minute, the system can bealternatively sized to provide a minimum total discharge volume ofliquid mist as a function of anticipated fire size in the enclosed spaceto be protected. For example, a preferred system design can provide atotal discharging liquid volume of mist to extinguish a fire for a givenunit of enclosure volume, the extinguishment volume, measured in litersper cubic meter (l./cu. m.) (gallons per cubic foot (gal./cu. ft.).Preferably, the total extinguishing volume of the liquid mist is lessthan about eight gallons (8 gal.) per each 130 cu. m. (4590 cu. ft.) ofenclosed space. More preferably the total extinguishing volume of thesystem ranges from 0.57 liters per cubic meter (0.57 liters/cu. m.)(0.0042 gallons per cubic foot (0.0042 gal./cu. ft.)) to 0.057 litersper cubic meter (0.057 liters/cu. m.) (0.00042 gallons per cubic foot(0.00042 gal./cu. ft.)) for a normalized range of fire sizes rangingfrom about one (1 kW/m³) to about eight (8 kW/m³).

Because the preferred design and method of operation of the preferredsystems can provide for a total volume to extinguish a fire, thepreferred system parameters can further define a range of times toextinguishment for a range of normalized fire sizes. In one aspect ofthe preferred method, the extinguishing times for a preferred systemranges from about 780 seconds to about 80 seconds, preferably from about500 seconds to about 80 seconds, and more preferably from about 420seconds to about 80 seconds, for a normalized range of fire sizesranging from about 1 kW/cu. m. to about 8 kW/cu. m.

Performance & Scalability

Three of the preferred mist systems described above were tested undervarious fire challenges in an enclosed space 120 measuring 7.72 m. (25.3ft.) (long) by 6.55 m. (21.5 ft.) (wide) by 5.1 (16.8 ft.) (tall) for avolume V of about 260 cu. m. (9180 cu. ft.) With reference back to FIGS.3A-3C the following systems: (i) mist system 300′ having two ceilingmounted atomizers 330′; (ii) mist systems 300″ having two sidewallmounted atomizers 330″; and (iii) mist system 400′ with a single ceilingmounted atomizers 430′. The atomizers of each system were located in apreferred manner as described above, with the ceiling mounted atomizersat a minimum clearance of about 1.2 m. (4 ft.) from the enclosure wall,and the sidewall atomizers located on the short walls to maximize itsdischarge distance.

Each of the systems was tested with a heptane fuel fire in which heatrelease rate (HRR) is varied as follow: 250 kW, 500 kW, 1000 kW and 2000kW. For each fire scenario, the fuel was located in a circular pan witha diameter that varied with the amount of fuel, Dia. (cm.)/Arnt of Fuel(liters), as follows: 45 cm./(16 liters) for the HRR of 250 kW; 62cm./(30 liters) for the HRR of 500 kW; 79 cm./(24.5 liters) for the HRRof 1000 kW; and 112 cm./(49 liters) for the HRR of 2000 kW. For each ofthe 1000 kW and 2000 KW fire, equal parts water was added to the fuel.The test fires were located on the floor in the geometric center of theenclosed space, underneath a (2.0 m.×2.0 m.) steel table obstruction,with the obstruction about 0.7 m. above the circular pan of fuel.Additionally, each fire was allowed to burn (pre-burn) for apredetermined period of time before the water mist suppression systemwas turned on. The 250 kW and 500 kW fires were allowed to pre-burn for120 seconds, and the 1000 kW and 2000 kW fires were allowed to pre-burnfor 30 seconds.

For each fire scenario, each of the two atomizer systems 300′, 400′ wastested first with a water flow rate to nitrogen gas pressure of 5.7 lpm(1.5 gpm) for 6.9 bar (100 psi.) delivered to each atomizer, and thensubsequently tested with a water flow rate to nitrogen gas pressure ofabout 9.5 lpm (2.5 gpm) for 12.1 bar (175 psi.) deliver to eachatomizer. The single atomizer system was tested first with a water flowrate to nitrogen gas pressure of 11.4 lpm (3 gpm) for 13.8 bar (200psi.) delivered to each atomizer, Each of the systems was tested with aheptane fuel fire by measuring, for a given heat release rate: (i) thesystem's time to extinguishment; (ii) total mist volume discharge at thetime of extinguishment; and (iii) oxygen concentration in the enclosedspace 120 at the time of extinguishment.

Summary of Test Results for Two Ceiling Mount Atomizers Fire SizeNormalized Pressure to Total Flow Rate HRR Fire Size Ea. Atomizer FromSystem Time To Final O2 Total Flow at [kW] [kW/cu. m.] [bar (psi.)] [lpm(gpm)] Ext. [sec.] [%] Ext. [L. (gal.)] 2000 7.69  6.9 (100) 11.4 (3.0)111 15.4 21.2 (5.6)  2000 7.69 12.1 (175) 17.8 (4.7) 111 15.5 32.9(8.7)  1000 3.85  6.9 (100) 11.4 (3.0) 374 15.7 70.8 (18.7) 1000 3.8512.1 (175) 18.2 (4.8) 216 15.4 86.3 (22.8) 500 1.92  6.9 (100) 11.4(3.0) 455 15.4 86.3 (22.8) 500 1.92 12.1 (175) 18.9 (5.0) 301 15.0 95.0(25.1) 250 0.96  6.9 (100) 11.4 (3.0) 1018 15.0  193 (50.9) 250 0.9612.1 (175) 18.9 (5.0) 431 15.1  136 (35.9)

Summary of Test Results for Two Sidewall Mount Atomizers Total FlowNormalized Pressure to Rate From Fire Size Fire Size Ea. Atomizer SystemTime To Final O2 Total Flow at Ext. HRR [kW] [kW/cu. m.] [bar (psi.)][lpm (gpm)] Ext. [sec.] [%] [L. (gal.)] 2000 7.69  6.9 (100) 11.4 (3.0)82 17.0 15.5 (4.1)  2000 7.69 12.1 (175) 18.9 (5.0) 85 16.0 26.9 (7.1) 1000 3.85  6.9 (100) 11.4 (3.0) 224 16.8 42.4 (11.2) 1000 3.85 12.1(175) 18.9 (5.0) 164 17.0 51.9 (13.7) 500 1.92  6.9 (100) 11.4 (3.0) 34916.5 66.2 (17.5) 500 1.92 12.1 (175) 18.9 (5.0) 319 15.6  101 (26.6) 2500.96  6.9 (100) 11.4 (3.0) 866 15.6  164 (43.3) 250 0.96 12.1 (175) 18.9(5.0) 501 15.3  158 (41.8)

Summary of Test Results for Single Ceiling Mount Atomizers Total FlowNormalized Pressure to Rate From Fire Size Fire Size Ea. Atomizer SystemTime To Ext. Final Total Flow at Ext. HRR kW] [kW/cu. m.] [bar (psi.)][lpm (gpm)] [sec.] O2 [%] [L. (gal.)] 2000 7.69 13.8 (200) 11.4 (3.0)145 14.7 27.6 (7.3)  1000 3.85 13.8 (200) 11.4 (3.0) 237 15.2 45.0(11.9) 500 1.92 13.8 (200) 11.4 (3.0) 500 16.1 94.6 (25.0) 250 0.96 13.8(200) 11.4 (3.0) 766 16.1  145 (38.3)

Successful fire test results demonstrate the capability of the preferredsystems and methods described herein to provide effective fireprotection. Moreover, the fire tests demonstrate that the systemperformance is influenced by, e.g., one or more of the input systemparameters discussed above.

For example, shown in FIG. 9 are three plots for the total waterconsumption to extinguishment over a range of nominal normalized firesizes in the preferred systems 300′, 300″, 400′ described above. Thenormalized fire is the fire size per unit volume of the enclosuremeasured in kilowatts per cubic meter (kW/cu. m.). Plot 600 shows thewater consumption to extinguishment for the preferred system 300′ inwhich two atomizers 330′ are ceiling mounted. Plot 602 shows the waterconsumption to extinguishment for the preferred system 400′ in which asingle atomizer 430′ is ceiling mounted. Plot 604 shows the waterconsumption to extinguishment for the preferred system 300″ in which twoatomizers 330″ are sidewall mounted.

The three plots 600, 602, 604 are substantially similar over the rangeof nominal normalized fire sizes. The plots 600, 602, 604 thereforeillustrate that the preferred systems and methods provide substantiallyconstant fire protection performance regardless of where or in whatmanner the atomizers are mounted within the enclosure. Morespecifically, the plots 600, 602, 604 indicate that a single atomizersystem can perform the same as a dual atomizer system, i.e., requiresubstantially the same amount of water to extinguishment, for a commonrange of nominal fire sizes, preferably ranging from about 1 kW/cu. m.to 8 kW/cu. m. Therefore, it is believed that a preferred system havinga single atomizer can perform the same as a system with two atomizersprovided their total flow rates are equal. Thus, a system 400′ with asingle atomizer 430′ can be appropriately scaled by discharging liquidat a flow rate of 11.4 lpm (3 gpm) to provide equal fire protection as asystem 300′, 300″ having two atomizers 330′, 330″ each discharging at aflow rate of 5.7 lpm (1.5 gpm). The other plots 606, 608 respectivelyshow the performance of a known high pressure water mist system and alow pressure water mist system, each of which require a greater amountof water for extinguishment.

Another set of performance plots 700, 702, 704 is provided at FIG. 10,in which each plot shows the time to extinguishment for a nominalnormalized fire heat release rate. Plot 700 shows the time toextinguishment for the preferred system 300′ in which two atomizers 330′are ceiling mounted. Plot 702 shows the time to extinguishment for thepreferred system 400′ in which a single atomizer 430′ is ceilingmounted. Plot 704 shows the time to extinguishment for the preferredsystem 300″ in which two atomizers 330″ are sidewall mounted. The otherplots 706, 708 of FIG. 10 show the time to extinguishment respectivelyfor a known high pressure mist system and a low pressure mist system.The plots 700, 702, 704 for the preferred systems substantially convergefor a normalized fire size of about 8 kW/cu. m. and only vary relativelyslightly as the normalized fire size decreases. Again, the plots 700,702, 704 demonstrate that the preferred systems can be configured toprovide substantially the same fire protection performance, i.e., timeto extinguishment, independent of the mounting orientation and/orlocation of the atomizers within the enclosure being protected.Moreover, the plots illustrate substantially equal performance fromsingle atomizer as compared to a system with two atomizers provided eachsystem has a substantially constant or equivalent total volume ofdischarge into the volume. At the lower range of normalized fire sizes,the plots illustrate the ability of the preferred systems 300′, 300″,400′ to have a shorter time to extinguishment when compared to eitherthe known high pressure water mist system or a low pressure mist system.

Additional tests were conducted to demonstrate the scalability of thepreferred systems to provide mist fire protection to larger enclosedsystems beyond 260 cu. m. (9180 cu. ft.) In particular, fire tests wereconducted to evaluate the performance of the preferred water mist systemin an enclosed space measuring 13 m. (42.5 ft.) long by 10. m. (32.8ft.) wide by 8.0 m. (26.2 ft.) tall for a volume V of about 1040 cu. m.(36,700 cu. ft.) with a ventilation opening of 4 sq. m. on one of thetwo shorter walls. Ceiling mounted atomizers in a pendent orientationwere utilized for all tests. The performance of the two pendent atomizersystem 300′ for the 260 cu. m. (9180 cu. ft.) enclosure, in which eachatomizer was provided with 6.9 bar (100 psi.) of gas pressure and awater flow rate of 5.7 lpm (1.5 gpm) corresponding to a total systemflow rate of 11.4 lpm (3 gpm), was used as a comparative basis in orderto evaluate the performance of a larger enclosure system.

A test fire with a nominal heat release rate of 2000 kW was utilized forall tests. For each fire, 38 liters (10 gallons) of heptane fuel andapproximately 38 liters (10 gallons) of water was located in a circularpan with a diameter of 112 cm. The test fires were located on the floorin the geometric center of the enclosed space, underneath a (2.0 m.×2.0m.) steel table obstruction, with the obstruction about 0.7 m. above thecircular pan of fuel. Each test fire was allowed to pre-burn for 30seconds prior to initiation of the mist suppression system.

Three tests were conducted on a preferred water mist system configuredfor the protection of an enclosed spaced having a free volume of 1040cu. m. (36,700 cu. ft), four times the volume of the base enclosure 260cu. m. (9180 cu. ft.). In each test, a system parameter was varied andthe performance of the system measured to evaluate the scalability ofthe preferred water mist systems with respect to the varied parameter.

In the first test, Test 1, the number of atomizers was increasedproportionally to the room size. Accordingly, with the free volumeincreased four times, test 1 increased the number of atomizers from two(2) to a total of eight (8) atomizers. The atomizers were installed inan evenly spaced grid pattern on the enclosure ceiling which consistedof two rows of four atomizers nominally 5.0 m. (16.4 ft.) by 3.25 m(10.7 ft.) apart. The flow rate to each atomizer was held at theconstant rate of 5.7 lpm (1.5 gpm) and the operating gas pressure washeld at 6.9 bar (100 psi.) Accordingly, the system of Test 1 providedfor a total system flow of 45.4 lpm (12 gpm).

In the second test, Test 2, the number of atomizers was increased fromtwo (2) to a total of four (4) atomizers. The eight (8) atomizersutilized in test 1 were left in their original installation location,but the fluid supply to every other atomizer was shut off, resulting inthe stated total of four (4) functional atomizers in a staggeredpattern. The flow rate to each atomizer was held at the constant rate of5.7 lpm (1.5 gpm) and the operating gas pressure was held at 6.9 bar(100 psi.) Accordingly, the system of Test 2 provided for a total systemflow of 22.7 lpm (6 gpm).

In the third test, Test 3, the test system was again provided with thesame four functional atomizers utilized in test 2, but this time theflow rate to each was increased. More specifically, the flow rate ofwater to each atomizer was doubled from 5.7 lpm (1.5 gpm) to 11.4 lpm (3gpm). The gas pressure to each atomizer was also doubled from 6.9 bar(100 psi.) to 13.8 bar (200 psi.). Accordingly, the system of Test 3provided for a total system flow of 45.4 lpm (12 gpm.).

For each test set up, a 2 kW fire was addressed and extinguished by thetest system. The time to extinguishment for each system was recordedalong with the total water discharged at the time of extinguishment. Thefinal oxygen concentration in the room at the time of extinguishment wasalso recorded. The system of Test 1 was tested twice; once with the 1040cu. m. (36,700 cu. ft.) enclosure space vented through a 4.0 squaremeter (43.1 sq. ft.) ventilation opening and once with the enclosurespace not vented. Results of the tests is provided below:

Summary of Results for Ceiling Mounted Atomizers in a 1040 cu. m.Enclosure Fire Size Normalized Pressure to Total Flow Rate Time To HRRFire Size Qty of Ea. Atomizer From System Ext. Final Total Flow at [kW][kW/cu. m.] Atomizers [bar (psi.)] [lpm (gpm)] [sec.] O2 [%] Ext. [L.(gal.)] 2000 1.9 8 6.9 (100) 45.4 (12.0) 390 15.0 295 (78.0) 2000 1.9 86.9 (100) 45.4 (12.0) 390 15.0 295 (78.0) 2000 1.9 8 6.9 (100) 45.4(12.0) 253 15.4 192 (50.6) 2000 1.9 4 6.9 (100) 22.7 (6.0)  430 15.4 163(43.0) 2000 1.9 4 6.9 (100) 22.7 (6.0)  459 15.2 174 (45.9) 2000 1.9 46.9 (100) 22.7 (6.0)  344 15.0 130 (34.4) 2000 1.9 4 6.9 (100) 22.7(6.0)  348 15.0 132 (34.8) 2000 1.9 4  10 (145) 30.3 (8.0)  353 15.0 178(47.1) 2000 1.9 4 13.8 (200)  45.4 (12.0) 381 14.8 288 (76.2) 2000 1.9 413.8 (200)  45.4 (12.0) 193 14.8 146 (38.6)

From the test results, the applicants have concluded that a 1040 cubicmeter (36,700 cu. ft.) enclosure with a 4 square meter (43.1 sq. ft.)ventilation opening can be protected with at least as few as 4 totalatomizers and an overall water flow rate of 22.7 lpm (6 gallons perminute). The high velocity spray plume of the atomizer generates asignificant amount of turbulence, rapidly filling the protected spacewith water mist. As a result, fire extinguishment performance appears tobe independent of both the number of devices utilized, and their overallorientation within the compartment.

The overall results of the testing in the 1040 cubic meter (36,700 cu.ft.) enclosure were consistent with those of the testing in the 260cubic meter (9180 cu. ft.) enclosure for a constant normalized firesize. This suggests that the extinguishing performance of the systemremains constant as long as the water-to-gas mass flow ratio is heldconstant, and the total flow rate of water discharged into the protectedspace is scaled linearly with enclosure volume.

The overall time to extinguishment marginally increased while the totalquantity of water required to extinguish the fire significantlydecreased when the total water flow rate was reduced from 45.4 liters(12 gallons per minute) to 22.7 liters per minute (6 gallons perminute), the number of discharging atomizers was reduced from 8 to 4,and nitrogen pressure was held constant at 6.9 bar (100 psi.)

When tested in the 1040 cubic meter (36,700 cu. ft.) enclosure, thesystem demonstrated nearly identical performance when tested with 8atomizers set at 5.7 liters (1.5 gallons per minute) each water flow and6.9 bar (100 psi) nitrogen pressure, and 4 atomizers set at 11.4 litersper minute (3.0 gallons per minute) each water flow and 13.8 bar (200psi) nitrogen pressure. These settings corresponded to a water-to-gasmass flow ratio of approximately 2.25:1. Extinguishment times at 200 psinitrogen pressure were marginally shorter than those observed at 6.9 bar(100 psi) nitrogen pressure. This suggests that overall turbulenceincreases as a result of the increase in spray plume velocity atincreased gas pressures.

Closing off the 4 square meter ventilation opening resulted in anincrease of approximately 25-50% in performance (as defined by time toextinguishment and total water discharged at extinguishment). Thecompressed nitrogen utilized to atomize the water appeared to maintain ahigher pressure within the enclosure with respect to the externalenvironment, subsequently reducing the quantity of fresh air which wasdrawn through the ventilation opening. It is surmised that ventilationeffects can be significantly reduced if not eliminated by pressurizingan enclosure with a high enough introduction rate of inert gas such asnitrogen into the space.

FM Testing

The above referenced fire tests were conducted in accordance withFactory Mutual Global (“FM Global”) Standard 5560 (May 2005), AppendicesD, E, and F, at pages 127 to page 146. Copies of the FM Standard 5560and the three test protocols are attached to U.S. Provisional PatentApplication No. 60/989,083 and are incorporated by reference in theirentireties. Fire tests can be conducted in accordance with alternatestandards such as, for example, IMO, VDS, UL, CCCF, etc. Morespecifically, fire tests were conducted to illustrate the effectivenessof the preferred method in providing water mist fire protection for: (i)Machinery Spaces; (ii) Special Hazard Machinery Spaces; and (iii)Combustion Turbine Enclosures. The three test protocols provide for eachone of (i) a diesel and a heptane fuel test, (ii) a total of five firetests for machinery spaces and (iii) seven tests for insulatedcombustion turbines. Preferably, the diesel fuel is high flash pointdiesel used preferably in normal hazard and combustion turbines, and theheptane fuel is of a low flash point special hazard type. Each of thefires tested ranged between about 1 megawatt to just over 2 megawatt(1-2 MW) and was configured as any one of a small shielded fuel sprayfire, a soaked insulation matt fire, a ventilated fuel fire, a pool fireand a pan fire.

Each of the fire test scenarios was conducted using two preferred twoatomizer mist system 300′ and single atomizer mist system 400′. Thefirst preferred system 300′ having two atomizers 330″ was evaluated in a260 cubic meter (9180 cu. ft.) enclosed space 120 measuring generally6.6 m. (21.6 ft.) wide by 7.7 m. (25.3 ft.) long by 5.1 m. (16.8 ft.)high, and the second preferred system 400 having a single atomizer 430was evaluated in a 130 cu. m. (4590 cu. ft.) enclosure measuringgenerally 6.6 m. (21.6 ft.), wide by 3.9 m. (12.8 ft.) long by 5.1 m.(16.8 ft.) high. In accordance with the FM test requirements, theenclosed space included a personnel door, preferably (0.81 m. (2.7ft.)×2.03 m. (6.7 ft.)), located 2.7 m. (9 ft.) from one of theenclosure corners. Along one of the long walls of the enclosure, apreferably removable panel (1.22 m. (4.0 ft.)×2.44 m. (8.0 ft.) isprovided to provide enclosure access. The enclosed spaced 120 furtherincluded two hinged ceiling hatches (0.91 m. (3.0 ft.)×1.83 m. (6.0ft.)) in opposite diagonal corners to provide heat and smoke release atthe conclusion of the test.

Each of the systems 300′, 400′ was constructed and tested with itsatomizers 330′, 430′ initially ceiling mounted and then subsequentlytested with the atomizers sidewall mounted 300″, 400″. For each firetest, the atomizers 330′, 430′ were provided with a flow of water atabout 11.4 liters per minute (3 gpm) and a gas flow rate of 4.6 kg/min(150 scfm) at an operating pressure of about 6.9 bar (100 psi.). Thetotal water mist discharge time from the systems was about 10 minutes.

According to the fire test results for each of the preferred systems300′ and 400′, extinguishment of the test fire was achieved in less thanfive minutes with an end concentration of oxygen per volume within theenclosure space at or above fifteen percent by volume.

According to Appendix D of FM 5560, five tests are conducted: D1) anunshielded 1 MW diesel spray fire; D2) a shielded 1 MW diesel sprayfire; D3) a diesel pool fire; D4) a shielded 2 MW diesel spray fire withlimited natural ventilation; and D5) a shielded 2 MW diesel spray fireat the smaller enclosure volume.

Summary of FM Appendix D Test Results Class Water Nitrogen EstimatedTotal Water Total Mass 5560 Test Qty. of Nozzle Flow Rate pressure FireSize Ext. Time at Ext Density % Ext. Number Nozzles Spacing ft. [m] [gpm(lpm)] [bar (psi)] [kW] [sec] [liters (gal)] (g/m³) D.3.1 2  9.5 × 13.55.7 (1.5) 6.9 (100) 1000 145 27.4 (7.25) 105.19 (2.9 × 4.1) D.3.2 2  9.5× 13.5 5.7 (1.5) 6.9 (100) 1000 225  42.6 (11.25) 163.23 (2.9 × 4.1)D.3.2 2 13.5 × 17.5 5.7 (1.5) 6.9 (100) 1000 153 29.0 (7.65) 111.00 (4.1× 5.3) D.3.3 2  9.5 × 13.5 5.7 (1.5) 6.9 (100) 1541 145 27.4 (7.25)105.19 (2.9 × 4.1) D.3.4 2  9.5 × 13.5 5.7 (1.5) 6.9 (100) 2000 223 42.2 (11.15) 161.78 (2.9 × 4.1) D.3.5 1 — 5.7 (1.5) 6.9 (100) 2000 10519.9 (5.25) 152.35

According to Appendix E of FM 5560, five tests are conducted: E1) anunshielded 1 MW Heptane spray fire; E2) a shielded 1 MW Heptane sprayfire; E3) a shielded 10.8 cu. ft. (1 cu. m.) Heptane Pool Fire; E4) ashielded 2 MW Heptane spray fire with limited natural ventilation; andE5) a shielded 2 MW diesel spray fire at the smaller enclosure volume.

Summary of FM Appendix E Test Results Class Water Nitrogen EstimatedTotal Water Total Mass 5560 Test Qty. of Nozzle Flow Rate pressure FireSize Ext. Time at Ext Density % Ext. Number Nozzles Spacing ft. [m] [gpm(lpm)] [bar (psi)] [kW] [sec] [liters (gal)] (g/m³) E.3.1 2  9.5 × 13.55.7 (1.5) 6.9 (100) 1000 196 37.1 (9.8)  284.38 (2.9 × 4.1) E.3.2 2  9.5× 13.5 5.7 (1.5) 6.9 (100) 1000 208 39.4 (10.4) 301.80 (2.9 × 4.1) E.3.32  9.5 × 13.5 5.7 (1.5) 6.9 (100) 2900 133 25.2 (6.65) 192.97 (2.9 ×4.1) E.3.4 2  9.5 × 13.5 5.7 (1.5) 6.9 (100) 2000 204 38.6 (10.2) 295.99(2.9 × 4.1) E.3.4 2 13.5 × 17.5 5.7 (1.5) 6.9 (100) 2000 203 38.6 (10.2)294.54 (4.1 × 5.3) E.3.5 1 — 5.7 (1.5) 6.9 (100) 2000 105 19.9 (5.25)152.35

According to Appendix F of FM 5560, five tests are conducted: F1) anunshielded 1 MW diesel spray fire; F2) a shielded 1 MW diesel sprayfire; F3) a shielded 10.8 cu. ft. (1 cu. m.) diesel Pool Fire; F4) ashielded 2 MW diesel spray fire with limited natural ventilation; andF5) a shielded 2 MW diesel spray fire at the smaller enclosure volume;F7) a saturated insulation mat and spray fire; and F8) a large saturatedinsulation mat.

Summary of FM Appendix F Test Results Class Nozzle Water NitrogenEstimated Total Water at Total Mass 5560 Test Qty. of Nozzle Spacing ft.Flow Rate pressure Fire Size Ext. Time Ext Density % Ext. Number NozzlesOrientation [m] [gpm (lpm)] [bar (psi)] [kW] [sec] [liters (gal)] (g/m³)F.3.1 2 Ceiling  9.5 × 13.5 5.7 (1.5) 6.9 (100) 1000 145 27.4 (7.25)105.19 (2.9 × 4.1) F.3.2 2 Ceiling  9.5 × 13.5 5.7 (1.5) 6.9 (100) 1000225  42.6 (11.25) 163.23 (2.9 × 4.1) F.3.2 2 Ceiling 13.5 × 17.5 5.7(1.5) 6.9 (100) 1000 153 29.0 (7.65) 111.00 (4.1 × 5.3) F.3.3 2 Ceiling 9.5 × 13.5 5.7 (1.5) 6.9 (100) 1541 145 27.4 (7.25) 105.19 (2.9 × 4.1)F.3.4 2 Ceiling  9.5 × 13.5 5.7 (1.5) 6.9 (100) 2000 223  42.4 (11.15)161.78 (2.9 × 4.1) F.3.5 1 Ceiling — 5.7 (1.5) 6.9 (100) 2000 105 19.9(5.25) 152.35 F.3.1 2 Sidewall 14.9 × 25.5 5.7 (1.5) 6.9 (100) 1000 24245.8 (12.1) 175.56 (4.6 × 6.6) F.3.2 2 Sidewall 14.9 × 25.5 5.7 (1.5)6.9 (100) 1000 214 40.5 (10.7) 155.25 (4.6 × 6.6) F.3.3 2 Sidewall 14.9× 25.5 5.7 (1.5) 6.9 (100) 1541 242 45.8 (12.1) 175.56 (4.6 × 6.6) F.3.42 Sidewall 14.9 × 25.5  6.6 (1.75) 7.6 (110) 2000 147 27.8 (7.35) 106.64(4.6 × 6.6) F.3.5 1 Sidewall — 5.7 (1.5) 6.9 (100) 2000 255  48.3(12.75) 369.99 F.3.7 2 Ceiling  9.5 × 13.5 5.7 (1.5) 6.9 (100) 1100 18334.6 (9.15) 265.52 (2.9 × 4.1) F.3.7 2 Sidewall 14.9 × 25.5 5.7 (1.5)6.9 (100) 1100 197 37.3 (9.85) 285.83 (4.6 × 6.6) F.3.8 2 Ceiling  9.5 ×13.5 5.7 (1.5) 6.9 (100) 1541 279  52.8 (13.95) 404.81 (2.9 × 4.1) F.3.82 Ceiling 13.5 × 17.5 5.7 (1.5) 6.9 (100) 1541 240 45.4 (12.0) 348.23(4.1 × 5.3) F.3.8 2 Sidewall 14.9 × 25.5 5.7 (1.5) 6.9 (100) 1541 257 48.6 (12.85) 372.89 (4.6 × 6.6)

Because of the successful test results, the preferred systems andmethods are believed to provide industrial fire protection in enclosedspaces at least up one thousand forty cubic meters (1040 cu. m.) forspecial hazard applications including, but not limited to: (i) oil pumpsand tanks; (ii) fuel filters; (iii) generators; (iv) transformer vaults;(v) diesel driven generators; (vi) gear boxes; (vii) drive shafts;(viii) lubrication skids; (ix) combustion turbines; (x) internalcombustion engines; (xi) hydraulic power packs; (xii) paint booths;(xiii) engine test cells, (xiv) solvent handling cells; and (xv)flammable liquid storerooms.

The preferred systems and methods have a demonstrated ability to provideeffective fire protection more efficiently than known water mist systemsor conventional water spray or sprinkler systems. In particular, thetable below illustrates that the preferred method and system of fireprotection provides effective fire protection with at least one of (i)less water; and (ii) at lower pressure; when compared to known high orlow pressure water mist systems. Table 1 below shows respectively thetotal water consumption required and the corresponding pressure requiredfor total flooding extinguishment of a nominal 1 MW fire for each of thepreferred water mist system, a known high pressure mist system, and aknown low pressure mist system.

Test Data - (Sealed Compartment Data Only) Min. Operating Ref. FlowPressure Rate 1 kW/m³ 2 kW/m³ 4 kW/m³ 8 kW/m³ System [bar (psi)] [lpm(gpm)] (97 BTU/ft³hr) (194 BTU/ft³hr) (388 BTU/ft³hr) (776 BTU/ft³hr)Water Consumption [liters (gallons)] Preferred System 6.9 (100) 11.4(3.0)   164 (43.3) 66.2 (17.5)    42 (11.2) 15.5 (4.1) 300, 400* KnownHigh   80 (1160)   30 (7.9) 1305 (345) 270 (71.3) 135 (36)   50 (13.2)Pressure Mist (HI- FOG ®) Known Low 12.4 (180)   48.5 (12.8) 1358 (359)548 (145)  242.5 (64)   111.5 (29.5) Pressure Mist (AQUAMIST ® from TYCOFIRE PRODUCTS LP) Extinguishment Time [seconds] Preferred System 6.9(100) 11.4 (3.0) 866 349 224 82 300, 400* Known High   80 (1160)   30(7.9) 2630 542 270 100 Pressure Mist (HI- FOG ®) Known Low 12.4 (180)  48.5 (12.8) 1691 678 298 137 Pressure Mist (AQUAMIST ® from TYCO FIREPRODUCTS LP) *System tested in a slightly larger compartment thanreferenced High Pressure and Low Pressure systems.

A Preferred Atomizing Device

One preferred atomizer 1000 for use in the above water mist systems isshown in FIGS. 11, 13, 14 and 15. The atomizer 1000 is a twin fluid mistgenerating device having a first fluid passage 1080 and a second fluidpassage 1090. The first and second fluid passages 1080, 1090 of theatomizer 1000 are defined by the manner in which the components of thedevice interconnect and interrelate with one another. The components ofthe atomizer 1000 generally include: a base 1012, a funnel 1030, a plug1050 and a cover 1070.

The base 1012 is preferably a generally circular member having a rearface 1014, a front face 1016 and first and second fluid inlet passages1018, 1020 adapted to receive respectively the liquid and gas from theirrespective fluid supply sources (not shown). Each of the fluid inletpassages 1018, 1020 is substantially parallel with the longitudinal axisL of the apparatus. Extending longitudinally through the centre of thebase 1012 is a bore 1017.

The funnel 1030 is engaged with the base 1012 so that the base 1012 andthe funnel 1030 are concentrically disposed about the longitudinal axisL. The funnel 1030 has a first end 1044, a second end 1042 and a bore1046 extending longitudinally through the funnel 1030 from the first end1044 to the second end 1042 to generally define the second fluid passage1090. The bore 1046 has an inlet 1047 at the first end 1044, an outlet1048 at the second end 1042, and a throat portion 1049 intermediate theinlet 1047 and the outlet 1048. At the inlet 1047 the bore 1046 has adiameter D1, at the throat portion 1049 the diameter of the bore 1046 isD2, and at the outlet 1048 the diameter of the bore is D3. The diameterD1 at the inlet 1047 is greater than the diameter D2 or D3, whilst thediameter D2 at the throat portion 1049 is less than the diameters D1 andD3. As a result, the bore 1046 narrows from its widest point at theinlet 1047 to a narrow diameter at the throat portion 1049 beforewidening again until it reaches the outlet 1048. The funnel 1030 ispreferably formed as a single piece member having a radially extendingflange portion 1032 and an axially projecting body portion 1034. Thebody portion 1034 has an outer surface 1037. An annular lip portion 1031extends rearwards from the flange portion 1032 defining a first fluidpassage 1038 and an inspection port 1039.

The plug 1050 is an elongate member having a first end 1051 and a secondend 1052. The plug 1050 has a first generally cylindrical portion 1053and a second conical portion 1055 extending from, and preferablyintegrally formed with, the cylindrical portion 1053. The conicalportion 1055 has a smallest diameter D4 adjacent the cylindrical portion1053 and its largest diameter D5 at the second end 1052 of the plug1050. The plug 1050 is engaged with the base 1012 such that the conicalportion 1055 of the plug 1050 provides a solid protrusion disposed inthe bore 1046 of the funnel 1030. More specifically, the inner surfaceof the bore 1046 and outer surface of the plug 1050 define a preferredconfiguration of the second fluid passage 1090.

The inlet 1047 of the funnel bore 1046 acts as the inlet of the secondfluid passage 1090. The second fluid passage 1090 further includes athroat portion 1092 adjacent the throat 1049 of the bore 1046 of thefunnel, and an outlet 1094 adjacent the respective second ends 1042,1052 of the funnel 1030 and plug 1050. As a result of the previouslymentioned variations in the diameter of the bore 1046 and the outwardtaper of the conical portion 1055 of the plug 1050, the second fluidpassage 1090 has a convergent-divergent internal geometry. In otherwords, the cross-sectional area of the throat portion 1092 of thepassage 1090 is considerably smaller than that of the inlet 1047 and theoutlet 1094. The cross sectional area of the passage 1090 at the outlet1094 is preferably greater than that at the throat portion 1092, butless than that at the inlet 1047. The total volume of the second fluidpassage 1090 from inlet 1047 to outlet 1094 may be about 24,900 cu. mm.and is more preferably between 24.3 cu. cm. (1.48 cu. in.) and 25.500cu. cm (1.56 cu. in.).

The cover 1070 is axially placed on the base 1012 such that the cover isthen concentric with the other components about the axis L. The cover1070 is generally dome-shaped, having a first end 1072 of largerdiameter than a second end 1074. Projecting axially from the second end1074 of the cover 1070 is an annular lip 1076. Referring to FIG. 21, thelip 1076 forms an outer surface to the cover 1070 over which a dust cap1002 or other protective covering that can be secured to preventcontaminant from entering the atomizer through the discharge space 508when the system is in a non-actuated state. As discussed above, thecover 1002 is disposed about the lip 1076 such that the discharge fluidsfrom the atomizer dislodge the dust cap 1002 from the lip 1076.

Referring back to FIG. 16, the lip 1076 has an internal surface 1078which defines a chamber or bore of substantially constant diameter. Thecover 1070 has a first section adjacent the first end 1072 which has afirst inner surface 1073 of substantially constant diameter. A secondsection of the cover 1070 extending between the first section and thelip 1076 has a second inner surface 1075. The diameter of the secondsection reduces in the direction of the second end 1074. Morepreferably, the second inner surface 1075 has a smooth inwardly curvingprofile as it progresses towards the second end 1074, with no steps orangles present on the inner surface 1075. The second inner surface 1075of the cover 1070 and the outer surface 1037 of the funnel 1030 definethe first fluid passage 1080 having an inlet 1082 and an outlet 1084.The inlet 1082 of the first fluid passage 1080 is in fluid communicationwith the first fluid inlet 1018 of the base 1012 and first fluid passage1038 of the funnel 1030. Due to the contours of the second inner surface1075 of the cover and outer surface 1037 of the funnel the first fluidpassage 1080 has a divergent-convergent internal geometry. In otherwords, the cross sectional area of a portion of the first fluid passage1080 intermediate the inlet 1082 and outlet 1084 is greater than thecross sectional area at either the inlet 1082 or outlet 1084. The crosssectional area of the first fluid passage 1080 progressively reducesfollowing the intermediate portion. The total volume of the first fluidpassage 1080 from inlet 1082 to outlet 1084 may be between 119000 cu. m.and 121500 cu. m.

FIG. 12A shows a detailed view of the respective outlets 1084,1094 ofthe first and second fluid passages 1080, 1090. Once the variouscomponents are correctly assembled, the outlet 1094 of the second fluidpassage 1090 is defined between the second ends 1052, 1042 of the plug1050 and funnel 1030. The outlet 1084 of the first fluid passage 1080 isdefined between the second end 1042 of the funnel 1030 and the innersurface 1078 of the lip 1076.

The way and means in which a mist is generated by the apparatus will nowbe described with particular reference to FIGS. 11, 12A and 12B.Initially, supplies of first and second fluids are connected to therespective first and second fluid inlets 1018, 1020 of the atomizer1000. The first fluid, also known as the working fluid, is a liquid firefighting agent, preferably water. The liquid is preferably introduced ata mass flow rate of between 4 kg/min and 20 kg/min at the first fluidinlet 1018. The liquid passes through the first fluid passage 1080 whichnarrows considerably in the direction of its outlet 1084 to define aworking nozzle. As a result of this narrow gap at the outlet 1084, theliquid ejects out of the outlet 1084 as a thin annulus of liquid,initially following a path represented in FIG. 12A by the dotted line1200. The initial path of the liquid 1200 from the outlet 1084 of thefirst passage 1080 is substantially parallel to the inner surface 1078of the lip 1076.

The second fluid, also known as the transport or carrier fluid, ispreferably a gas such as compressed air, nitrogen or helium, forexample. The gas is preferably introduced to the second fluid inlet 1020at a pressure of between 4 bar and 18 bar for passage through the secondfluid passage 1090 for ejection from the outlet 1094 to define atransport nozzle. Due to the reduction and subsequent increase in thecross sectional area of the second fluid passage 1090 between its inlet1047, throat 1092 and outlet 1094, the gas entering the inlet 1047 isaccelerated to a high, possibly even supersonic, velocity as it exitsthe outlet 1094. The gas may be discharged at a mass flow rate ofbetween 2 kg/min and 6 kg/min.

The angle of the second fluid passage 1090 is such that the acceleratedsecond fluid stream, whose initial trajectory is shown as dotted line1220 in FIG. 12A, exits the outlet 1094 and interacts with the annulusof liquid issuing from the outlet 1084. The angle of incidence betweenthe liquid and the gas streams 1200, 1220 is shown in FIG. 12A as angleα.

With reference to FIGS. 12A and 12B, an equivalent angle of expansionfor the second passage 1090 as it expands between the throat 1092 andthe outlet 1094 may be calculated. In particular, FIG. 12B showsschematically how this equivalent angle of expansion for the secondfluid passage can be calculated when the cross sectional areas of thethroat and outlet, and the equivalent path distance between the throatand outlet are known. E1 is the radius of a circle having the same crosssectional area as the throat of the second fluid passage. E2 is theradius of a circle having the same cross sectional area as the outlet ofthe second fluid passage. The distance d is the equivalent path distancebetween the throat and the outlet. An angle β is calculated by drawing aline through the top of E2 and E1 which intersects a continuation of theequivalent distance line d. This angle β can either be measured from ascale drawing or else calculated from trigonometry using the radii E1,E2 and the distance d. The equivalent angle of expansion for the secondfluid passage can then be calculated by multiplying the angle β by afactor of two, where γ=2β.

For optimum performance of the apparatus, it has been found that thecross sectional area of the throat portion 1092 of the second fluidpassage 1090 should preferably be between 20 mm² and 35 mm². The crosssectional area at the outlet 1094 of the second fluid passage may bebetween 1.1 and 28 times larger than that of the throat portion 1092,such that the area ratio between the throat 1092 and outlet 1094 of thesecond fluid passage 1090 may be between 10:11 and 1:28. The crosssectional area at the outlet 1094 of the second fluid passage may mostpreferably be between 1.4 and 5.5 times larger than that of the throatportion 1092, such that the area ratio between the throat 1092 andoutlet 1094 of the second fluid passage 1090 is therefore mostpreferably between 5:7 and 2:11. This increase in cross sectional areabetween the throat portion 1092 and outlet 1094 creates an equivalentincluded angle of expansion for the second fluid passage 1090 of between1 and 40 degrees, and an angle which is most preferably between 2 and 13degrees. Furthermore, the cross sectional area of the second fluidpassage outlet 1094 may be between 0.3 and 12 times larger than thecross sectional area of the first fluid passage outlet 1084, such thatthe area ratio between the first fluid outlet 1084 and second fluidoutlet 1094 is therefore between 10:3 and 1:12. The cross sectional areaof the second fluid passage outlet 1094 is most preferably between 1 and6 times larger than the cross sectional area of the first fluid passageoutlet 1084, such that the area ratio between the first fluid outlet1084 and second fluid outlet 1094 is therefore most preferably between1:1 and 1:6.

The stream of gas 1220 coming into contact with the stream of liquid1200 causes shear stripping of droplets from the annulus of liquid 1200due to Kelvin-Helmholtz and Raleigh-Taylor instabilities on the firstfluid surface. These instabilities cause ligaments of the liquid tobreak off from the annulus and form a dispersed droplet flow regime ofthe liquid and gas. In other words, a dispersed phase of the first fluiddroplets is dispersed in a continuous phase of the second fluid. As thedroplets are torn from the liquid stream 1200 they are accelerated bythe gas, causing further shear break-up. Where the gas exits the outlet1094 at a supersonic velocity, a supersonic Shockwave may be createddistal of the apparatus which may be beneficial to the atomizationmechanism. The Shockwave is created as the gas transitions fromsupersonic to subsonic speed. The Shockwave is created at the point oftransition from supersonic to subsonic speed. In this instance, thefirst fluid is further atomized by the Shockwave at the point oftransition.

The gas creates a turbulent region 1240 as it moves away from theapparatus and induces low velocity currents capable of transporting thedroplets of first fluid preferably through the surrounding space,preferably in a homogenous manner. This turbulent region 1240 is causedby rapid changes in the pressure and velocity of the gas generatingnumerous unsteady vortices and a swirling of the gas. The turbulentregion 1240 applies acceleration and deceleration forces on the dropletsof the liquid, leading to a further atomization of the droplets beingcarried by the second fluid. This atomization mechanism can becontrolled by, amongst other things, controlling the momentum flux ratiobetween the first and second fluids.

The momentum flux ratio M is defined by the equation

$M \equiv \frac{\left( {\rho_{s} \times U_{s}^{2}} \right)}{\left( {\rho_{f} \times U_{f}^{2}} \right)}$

where

-   -   ρ=Fluid density    -   U=Fluid velocity    -   s represents second fluid (gas)    -   f represents first fluid (liquid)

Thus, the momentum flux ratio between the liquid and gas can becontrolled by varying the density or velocity of the fluids. Thevelocity can be varied by adjusting the feed pressure while the densitycan be varied by changing the temperature of the fluid.

As most clearly shown in FIG. 12A, the liquid and gas streams 1200, 1220issuing from their respective outlets 1084, 1094 are angled relative toone another at an angle of incidence a. The angle of incidence a is theangle between the initial trajectories of the streams 1200, 1220, shownas clotted lines in FIG. 12A. These initial trajectories are dictated bythe inner wall 1043 of the first fluid passage 1080 and the outer wall1045 of the second fluid passage 1090 at their respective outlets 1084,1094. Thus, to obtain an angle of incidence in a desired range, theangle between these passage walls 1043, 1045 at the first and secondfluid outlets 1084, 1094 should be in the same range. In the embodimentillustrated, both the inner first passage wall 1043 and outer secondpassage wall 1045 are defined by the funnel 1030, as best seen in FIG.14. Referring again to FIG. 12A, the angle of incidence a causes thesecond fluid stream 122 to impinge on the annulus forming the firstfluid stream 120. The angle of incidence a is less than 90 degrees, andpreferably between 5 and 30 degrees. Most preferably, the angle ofincidence a is between 10 and 20 degrees.

The atomizers 1000, 1000′ and 1000″ of FIGS. 11, 17 and 18 provide meansfor atomizing a first fluid with a second fluid. In particular, each ofthe atomizers include first and second fluid passages 1080, 1090 eachdefining a fluid path and volume to discharge, engage and mix a streamof a liquid with a high velocity gas for atomization of the liquidstream for generation and distribution of a mist. However, alternativemeans can be provided to produce and engage a liquid stream and highvelocity gas to atomize and disperse the liquid as a mist. In view ofthe atomizers described herein, known mist generating devices could bemodified to discharge a liquid annulus from one fluid passage andaccelerate and discharge an inert gas from another fluid passage toatomize the liquid annulus for generation and distribution of a liquidmist in an enclosed space to be protected, and thus provide a means foratomizing a first fluid with a second fluid.

Referring again to FIG. 11, the inner surface 1078 of the lip 1076 ofcover 1070 ensures that larger droplets torn from the first fluid stream1200 that could be projected away from the longitudinal axis L of theapparatus by the second fluid stream 1220 are prevented from doing so toprovide for mixing of the liquid and the gas in the chamber of the lip1076. Furthermore, droplets held against the inner surface 1078 of thelip 1076 are more easily atomized as they are subject to both the forceof the second fluid and the friction forces from the inner surface 1078.

The atomization mechanism of the present invention is capable ofatomizing the liquid into a mist in which a large proportion, preferablygreater than 80% of the droplets, range in size from about 1 micron toabout 10 microns and more preferably ranging from about 1 micron toabout 5 microns. Shown in FIG. 22, for purposes of illustration is acumulative frequency size distribution of the droplets in the mistproduced by a preferred atomizer. According to the plot, the mistincludes a distribution of droplets in which more than 90% have adroplet size ranging between 1 to 10 microns in diameter. Thedischarging gas and annulus of liquid together preferably define asubstantially conical mist spray pattern. Referring to FIG. 20, the mistspray pattern for a preferred atomizer is illustrated in a sidecross-sectional view. The perimeter of the mist spray pattern define thecross-sectional area defines an included angle Δ of about 15° degrees(±2°) with the central axis of the atomizer, and therefore includedangle of 2Δ about 30° degrees (±2°) between the perimeter of the spraypattern defining the conical shape of the mist.

It has been determined that the conical spray pattern is substantiallyfully developed at an axial distance DZ of about 1.1 m. (42 inches) fromthe discharge end of the atomizer and more preferably fully developed atan axial distance DZ of about 1.6 m. (64 inches) from the discharge endof the atomizer. By “substantially fully developed” it is understoodthat the conical spray pattern has maximized its radial distance fromthe central axis of the atomizer so as to find an end circle of theconical spray pattern having a diameter D1A of about 0.6 m. (24 inches)at the axial distance of about 1.1 m. (42 inches) from the atomizer, andmore preferably having a diameter D1A of about 0.9 m. (36 inches) at theaxial distance of about 1.6 m. (64 inches) from the atomizer.

For the atomizing device 1000 shown in FIG. 11, applicants supplied aflow of water at 11.3 lpm (3 gpm) with a supply of nitrogen gas at 6.9bar (100 psi.) The resultant mist spray pattern was observed against ablack background and photographed. Shape and included angles of the mistspray pattern is calculated based upon the scale relationship betweenthe photograph and an actual dimensioned feature of the atomizer. Forexample, where the discharge end of the atomizer has a diameter of about40 mm. (1.57 inches) and in the photograph has a diameter of about 5.9mm. (0.232 inches) to define a photo scale factor of about 6.75.

The components of the atomizer 1000 will be described in greater detail.Referring to FIG. 13 is a longitudinal section view through the base1012. As noted above, the base 1012 is generally circular and has a rearface 1014, a front face 1016 and first and second fluid inlet passages1018, 1020 adapted to receive the first and second fluids from theirrespective sources (not shown). Each of the fluid inlet passages 1018,1020 is substantially parallel with the longitudinal axis L of theapparatus. Each fluid inlet passage 1018, 1020 has an internal threadadapted to receive the external thread of respective fluid supply pipes(not shown). Extending longitudinally through the centre of the base1012 is the bore 1017. Referring to FIG. 13A, the bore 1017 has agenerally triangular-shaped recess 1019 opening on the rear face 1014 ofthe base 1012. The base 1012 includes a radially extending flangeportion 1015 and an axially projecting annular projection 1022 whichprojects forwards from the front face 1016. A plurality ofcircumferentially spaced apertures 1021 extend longitudinally throughthe flange portion 1015. The annular projection 1022 has an innersurface 1024 and an outer surface 1026. The outer surface 1026 containsa groove 1027 in which an O-ring seal 1028 is located.

FIG. 14 shows the funnel 1030 as a projecting member preferably formedas a single piece having a radially extending flange portion 1032 and anaxially projecting body portion 1034. The body portion 1034 has an outersurface 1037. An annular lip portion 1031 extends rearwards from theflange portion 1032 and defines an outer surface 1033. The outer surface1033 contains a groove 1035 in which an O-ring seal 1036 is located. Theflange portion 1032 is annular and extends around the entirecircumference of the projecting member 1030. Defined within the flangeportion 1032 are a first fluid passage 1038 and an inspection port 1039.

As described above, the funnel 1030 has a first end 1044 and a secondend 1042 and a bore 1046 extending longitudinally through the funnel1030 from the first end 1044 to the second end 1042. The bore 1046 hasthe inlet 1047 at the first end 1044, the outlet 1048 at the second end1042, and the throat portion 1049 intermediate the inlet 1047 and outlet1048. The bore 1046 may have an axial length of between 52 mm and 55 mm.At the inlet 1047 the bore 1046 has a diameter D1 which may be between53 mm and 59 mm. At the throat portion 1049 the diameter of the bore1046 is D2 which may be between 7.5 mm and 13 mm, and at the outlet 1048the diameter of the bore is D3 which may be between 30 mm and 34 mm. Thediameter D1 at the inlet 1047 is greater than the diameter D2 or D3,whilst the diameter D2 at the throat portion 1049 is less than thediameters D1 and D3. As a result, the bore 1046 narrows from its widestpoint at the inlet 1047 to a narrow diameter at the throat portion 1049before widening again until it reaches the outlet 1048.

FIG. 15 shows the plug 1050 forming a further part of themist-generating apparatus. As described generally above, the plug 1050is an elongate member having a first end 1051 and a second end 1052. Theplug 1050 has a first generally cylindrical portion 1053 and a secondconical portion 1055 extending from, and preferably integrally formedwith, the cylindrical portion 1053. More preferably, part of thecylindrical portion 1053 adjacent the first end 1051 is provided with anexternal thread 1054. The conical portion 1055 is in the shape of aninverted cone, with the narrowest point of the cone adjacent thecylindrical portion 1053 and the widest point of the cone at the secondend 1052 of the plug 1050. The conical portion 1055 has a smallestdiameter D4 adjacent the cylindrical portion 1053 and a largest diameterD5 at the second end 1052 of the plug 1050. The cylindrical portion 1053has first and second grooves 1056, 1058 longitudinally spaced from oneanother and extending around the circumference of the cylindricalportion 1053. The first groove 1056 is a thread relief grooveco-operating with the external thread 1054. Also formed part way alongthe cylindrical portion 1053 is a radially projecting lip 1060, whichdefines an abutment surface 1062 facing towards the first end 1051 ofthe plug 1050. The second groove 1058 holds an O-ring seal 1057. Afurther groove 1059 is provided in the cylindrical portion 1053 of theplug 1050 adjacent the first end 1051.

The second end 1052 of the plug 1050, which is also the widest part ofthe conical portion 1055, has an end face which is concave. Thus, adish-shaped cavity 1064 is formed in the second end face of the plug1050. The end face of the second end 1052 also includes a pair oflocating holes 1061.

FIG. 16 shows the cover 1070 forming part of the mist-generatingapparatus. The cover 1070 is preferably generally dome-shaped, having afirst end 1072 of larger diameter than a second end 1074. Projectingaxially from the second end 1074 of the cover 1070 is an annular lip1076. The lip 1076 has an internal surface 1078 which defines a bore ofsubstantially constant diameter. In other words, the lip 1076 hasinternal walls which are substantially parallel when viewed in verticalcross-section, such as here in FIG. 16. The cover 1070 has a firstsection adjacent the first end 1072 which has a first inner surface 1073of substantially constant diameter. Located in the first end 1072 of thecover 1070 at circumferentially spaced intervals are a plurality ofaxially extending threaded holes 1088. A second section of the cover1070 extending between the first section and the lip 1076 has a secondinner surface 1075. The portion of the second section adjoining thefirst section has a smaller diameter than that of the first section,such that a rearward facing abutment 1071 is defined between the firstand second sections of the cover 1070. The diameter of the secondsection reduces in the direction of the second end 1074. In other words,the second inner surface 1075 tapers inwardly from the abutment 1071until it reaches the internal surface 1078 of the lip 1076. Thus, thesecond inner surface 1075 has a smooth inwardly curving profile as itprogresses towards the second end 1074, with no steps or angles presenton the inner surface 1075.

The manner in which the mist-generating apparatus, generally designated1000, is assembled will now be described with particular reference toFIGS. 11 and 11A. Firstly, each of the components shown in FIGS. 13-16is formed from a suitable material, which is preferably stainless steel.In the first step of assembling the apparatus 1000, the funnel 1030 isaxially inserted onto the base 1012 so that the base 1012 and funnel1030 are concentric about the longitudinal axis L, with the outersurface 1033 of the funnel lip 1031 being guided by the inner surface1024 of the annular projection 1022, until the rear face of the flangeportion 1032 abuts the surface of the annular projection 1022. TheO-ring seal 1036 located in the groove 1035 on the outer surface 1033ensures a sealing fit between the two components. When the base 1012 andfunnel 1030 are correctly positioned, the first fluid inlet passage 1018of the base 1012 and first fluid passage 1038 of the funnel are alignedand capable of fluid communication with one another. Furthermore, theinlet 1047 of the funnel bore 1046 and the second fluid inlet passage1020 of the base 1012 are now in fluid communication with one another aswell. Once the base 1012 and funnel 1030 have been correctly orientedwith respect to one another, a temporary locking ring (not shown) issecured over the flange portion 1032 of the funnel 1030 such that thebase 1012 and funnel 1030 are locked together.

Once the base 1012 and funnel 1030 are temporarily locked together, theplug 1050 can be introduced, firstly via the bore 1046 of the funnel1030 and then the bore 1017 of the base 1012. As best seen in FIG. 13A,a locking nut 1102 is inserted into the recess 1019. As the plug 1050 isinserted through the bores 1046,1017 it is rotated by a suitable tool(not shown) which locates in the locating holes 1061. As the plug 1050is rotated the threaded surface 1054 of the plug 1050 marries with theinternal thread of the locking nut 1102. The outer faces of the nut 1020contact the inner surfaces of the triangular recess 1019 such that therecess 1019 prevents the nut 1020 from rotating as the first end 1051and threaded surface 1054 of the plug 1050 are threaded through. The lip1060 of the plug 1050 has a larger diameter than the bore 1017.Consequently, once the abutment surface 1062 of the lip 1060 comes intocontact with the base 1012, the plug 1050 cannot be threaded any furtherthrough the nut 1020. At this point, a washer 1040 and circlip 106 arefitted to the first end 1051 of the plug 1050 so that the nut 1020cannot work itself loose. The circlip 106 locates in the groove 1059provided at the first end 1051 of the plug 1050. The O-ring seal 1057located in the cylindrical portion 1053 of the plug 1050 ensures asealing fit between the plug 1050 and the bore 1017.

As can be seen in FIG. 11, once the plug 1050 is axially andconcentrically located in the bore 1017, the conical portion 1055 of theplug 1050 lies between the throat portion 1049 and outlet 1048 of thebore 1046 in the funnel 1030. Consequently, the inner surface of thebore 1046 and outer surface of the plug 1050 now define a second fluidpassage 1090.

Once the plug 1050 has been fixed to the base 12, the inspection port1039 can be used to measure the axial distance between the top surfaceof the annular projection 1022 and the remote second ends 1042, 1052 ofthe funnel 1030 and plug 1050. This ensures that the base 1012, funnel1030 and plug 1050 are all correctly positioned relative to one another.At the same time, measuring instruments can be used to check the gapbetween the funnel 1030 and plug 1050 which forms the second fluidpassage 1090.

Once the measurement and positioning checks have been completed, thetemporary locking ring can be removed and replaced with the cover 1070.The cover 1070 is axially placed on the base 1012 such that the abutment1071 contacts the flange portion 1032 of the funnel 1030, and the coveris then concentric with the other components and the axis L. Thissandwiches the flange portion 1032 between the base 1012 and cover 1070,holding the base 1012 and funnel 1030 against one another. At the sametime, the O-ring seal 1028 ensures a sealing fit between the base 1012and cover 1070. The cover 1070 is aligned with the base 1012 so that thethreaded apertures 1088 align with the apertures 1021 in the base 1012.A plurality of fixing screws 1180 are then tightened into the threadedapertures 1088 via the apertures 1021 in the base 1012. Once the screws1180 are fully tightened the heads of the screws 1180 are at least flushwith the rear face 1014. A number of blind mounting holes 1100 withinternal threads are also provided on the rear face 1014 of the base1012 for attaching the apparatus to a suitable mounting skid or thelike.

As seen best in FIG. 11, once the cover 1070 is successfully fitted, thesecond inner surface 1075 of the cover 1070 and the outer surface 1037of the funnel 1030 define a first fluid passage 1080 having an inlet1082 and an outlet 1084. The inlet 1082 is in fluid communication withthe first fluid inlet 1018 and first fluid passage 1038. Due to thecontours of the second inner surface 1075 and outer surface 1037 thefirst fluid passage 1080 has a divergent-convergent internal geometry.In other words, the cross sectional area of a portion of the first fluidpassage 1080 intermediate the inlet 1082 and outlet 1084 is greater thanthe cross sectional area at either the inlet 1082 or outlet 1084. Thecross sectional area of the first fluid passage 1080 progressivelyreduces following the intermediate portion. The total volume of thefirst fluid passage 1080 from inlet 1082 to outlet 1084 is about 120,400cu. mm., and may be more preferably between 119,000 cu. mm. and 121,500cu. mm.

The ability of the atomizer 1000 to generate a mist, as described above,having the preferred droplet size distribution for the preferred waterflow rates and low gas pressures is believed to be a function of thegeometry of the first and second fluid passages 1080, 1090. The abilityof the liquid to form the desired thin annulus is a function of thefirst fluid passage 1080. Shown in FIG. 19 is detailed cross-sectionalview of the first fluid flow passage 1080. The profile of the passage1080 can be defined by a curve that is a function of the three criticalareas: (i) the inlet area A1 at the inlet area of the passage 1080; (ii)the outlet area A3 at the outlet area of the passage 1080; and (iii) themaximum intermediate area A3 between the inlet area A1 and the outletarea A3. Each of the critical areas A1, A2, A3 define a substantiallycircular area coaxially disposed along the central fluid path FP of thepassage 1080. The areas A1, A2 and A3 are separated from one anotheralong the path FP by a first fluid path distance L1 between areas A1 andA2 and a second fluid path distance L2 between areas A2 and A3.

Using the radii of the critical areas, A1, A2 and A3, the angular rateof change in radii from one area to the next adjacent can be determinedby their trigonometric relationship. The radii increases from the inletarea A1 to the intermediate area A2. In the preferred embodiment, theequivalent area A2 is larger than A1 by a factor of between 1 to 50, ispreferably between 1 to 5 and is more preferably about 1 to 1.5, so asto define a preferable angular change between the radii from A1 to A2 ofabout 83° degrees (82.7°). The radii increases from the outlet area A3to the intermediate area A2. In the preferred embodiment, the equivalentarea A2 is larger than A1 by a factor of between 50 to 400, preferably100 to 300, and more preferably 270 to 280, so as to define an angularchange between the radii from A3 to A1 of about 84° degrees (83.6°).

The profile of the passage 1080 is preferably smooth. Smoothness can bedefined as the angular spacing between adjacent discrete segments whichcan approximate the surface profile. Referring to FIG. 19A, shown is adetailed view of the wall profile of the passage 1080 has been broken upinto discrete segments and the angle of change between each segment ismeasured. The discrete segments are each about 1 percent of the fluidpath FP length. In a surface profile is smooth, then there is a smallangular change from one segment to the next having a maximum change ofabout 90°, preferably a maximum of 45°, even more preferably a max of45°, and is yet even more preferably less than 30 degrees. In contrast,if there is a sudden step in the profile, then the angular change isgreater. In the preferred embodiment of the atomizer, the segmentedprofile of the passage 1080 has a maximum angular change that is lessthan 30 degrees. More specifically, the surface of the passage 1080defined by the inner surface of the cover has a maximum angular changebetween adjacent segments of about 27° Degrees. The surface of thepassage 1080 defined by the outer surface of the funnel has a maximumangular change between adjacent segments of about 4.5° Degrees.

Returning again to FIG. 11, once the various components are correctlyassembled, the outlet 1094 of the second fluid passage 1090 is definedbetween the second ends 1052, 1042 of the plug 1050 and funnel 1030. Theoutlet 1084 of the first fluid passage 1080 is defined between thesecond end 1042 of the funnel 1030 and the inner surface 1078 of the lip1076.

An alternative embodiment of the atomizer is shown in FIGS. 18 and 18A.In the atomizer 1000″, the components are the same as those of theatomizer 1000 shown in FIG. 11. However, in this alternative embodiment,the funnel 1030″ and plug 1050″ are dimensioned so that the funnel andplug occupy the bore of the annular lip 1074″ at the second end 1074″ ofthe cover 1070″. The configuration of the atomizer 1000″ effectivelyeliminate the protruding lip by locating the first and second fluidoutlets 1084″, 1094″ adjacent the second end 1074″ of the cover 70″.

FIGS. 17 and 17A show views of another alternative embodiment of amist-generating apparatus in accordance with the present invention. Thealternative embodiment of the apparatus, generally designated 1000′,shares a number of components with the previously described embodimentand atomizes the first fluid in the same manner as described above.However, the alternative embodiment does also have a number ofdifferences from the first embodiment. Most noticeably, the second end1074′ of the cover 1070′ does not have a protruding lip. The second end1074′ is therefore adjacent the first and second fluid outlets 1084′,1094′. The funnel 1030′ of this alternative embodiment does not have aradially projecting flange portion which is sandwiched between the cover1070′ and the base 1012′. Instead, the funnel 1030′ is secured directlyto the base 1012′ by a number of fixing screws (not shown).Additionally, instead of being secured together by screw fixings thecover 1070′ has an internal thread on its inner surface 1073′ whichcooperates with an external thread on the outer surface 1026′ of thebase 1012′. The cover 1070′ can therefore be threaded onto the base1012′, and turning the cover 1070′ relative to the base 1012′ willadjust the axial distance between the cover 1070′ and both the base1012′ and the funnel 1030′ directly secured to the base 1012′.

As seen best in FIG. 17A, the first fluid outlet 1084′ has been adaptedin several ways in the alternative embodiment. Firstly, the width of thegap between the second ends 1042′, 1074′ of the funnel 1030′ and cover1070′ which forms the first fluid outlet 1084′ has been increased.Increasing the gap widens the first fluid outlet 1084′ and reduces theexit velocity of the first fluid for the same flow rate condition.Secondly, as the axial distance between the cover 1070′ and the funnel1030′ can be adjusted in this embodiment, the angle of projection andexit velocity of the first fluid can also be adjusted. Adjusting theaxial position of the cover 1070′ relative to the base 1012′ and funnel1030′ adjusts the relative axial positions of the second end 1074′ ofthe cover 1070′ and the second end 1042′ of the funnel 1030′, both ofwhich define the first fluid outlet 1084′. The adjustment of thesecomponents therefore also adjusts the gap size of the first fluid outlet1084′ and initial path 1200′ of the first fluid stream as it exitsthrough the first fluid outlet 1084′. As a result, the more the cover1070′ is screwed onto the base 1012′ the more the initial path of thefirst fluid stream 1200′ issuing from the outlet 1084′ will diverge fromthe longitudinal axis L′ of the apparatus 1000′. In the firstembodiment, the angle of projection was substantially parallel with thelongitudinal axis of the apparatus. The variation in the angle ofprojection also reduces the angle of incidence a′ between the first andsecond fluid streams 1200′, 1220′ issuing from their respective outlets1084′, 1094′.

The plug 1050′ in the alternative embodiment has a longer threadedsurface 1054′ and no lip portion limiting its axial position relative tothe base 1012′. The bore 1017′ in the base 1012′ has an internal threadwhich engages the threaded surface 1054′ of the plug 1050′. As a result,the axial position of the plug 1050′ relative to the base 1012′ and theother main components can be adjusted depending upon the amount that theplug 1050′ is screwed into the base 1012′. This also allows the width ofthe second fluid passage 1090′ and outlet 1094′ to be adjusted, as theposition of the plug 50′ can be adjusted relative to the funnel 30′.Consequently, the adjustment of the plug 1050′ also adjusts the arearatio between the throat and outlet of the second fluid passage, as wellas the equivalent angle of expansion of the second fluid passage. Oncethe plug 1050′ has been positioned such that the area ratio between thefirst and second outlets and the equivalent angle of expansion arewithin the ranges set forth above, a lock nut 1020″ is fitted over thefirst end 1051′ of the plug 1050′ protruding from the rear face 1014′ ofthe base 1012′.

The present invention provides a mist generating apparatus which has asingle supply channel for each of the first and second fluids. Thesupply channels are substantially parallel with the longitudinal axis ofthe apparatus, thereby reducing the supply pressures needed to supplythe fluids. Having single supply channels for each fluid which aresubstantially parallel to the longitudinal axis of the apparatus allowsthe apparatus and supply lines to be more easily manufactured andinstalled on a mounting skid or the like, in comparison to mistgenerators which have one or more supply channels which enter theapparatus perpendicular to the longitudinal axis.

The geometry of the fluid passages and their respective outlets alsoprovides the present invention with improved performance compared withexisting mist generators in terms of efficiency (the amount of secondfluid used to atomize the first fluid) and the degree of atomization ofthe first fluid. Specifically, the area ratio between the first andsecond fluid outlets, and the angle of incidence between the two streamsof the fluid exiting the outlets improve atomization performance in thepresent invention. By providing an area ratio between the respectiveoutlets as detailed above, the present invention provides a thin filmsheet of first fluid which can be atomized more efficiently by thesecond fluid. The smaller exit area of the first fluid outlet alsoincreases the exit velocity of the first fluid, which in itself can leadto a degree of atomization of the first fluid as it exits the apparatus.Providing an angle of incidence between the two streams which fallswithin the ranges detailed above provides improved atomization of thefirst fluid (in terms of droplet size and droplet distribution) whilstreducing the risk of the atomized first fluid droplets coalescingtogether again. The greater the angle of incidence between the streams,the greater the initial momentum transfer from the second fluid to thefirst fluid. However, a large angle of incidence also can lead to thefirst fluid film sheet converging when it comes into contact with thesecond fluid stream, increasing the risk that some of the atomized firstfluid droplets will coalesce back together.

Using the second fluid stream to create a turbulent region outside theapparatus ensures further atomization of the first fluid, againimproving the atomization performance of the present invention. Thus,the present invention provides a mist-generating apparatus which (i)generates a mist with the desired water droplet size, and (ii) generatesturbulence in the protection space for substantially homogenousdistribution of the water droplets throughout the volume of thesurrounding space.

The method in which the apparatus is assembled also has benefits. Thebase, funnel, plug and cover are all assembled concentrically in such away that the gaps defining the fluid passages and outlets between thecomponents are consistent along the length and around the circumferenceof the apparatus. Furthermore, as each of the funnel, plug and cover areattached or mounted to the base plate, the components have a commonreference point. This ensures that tolerance errors are minimizedinstead of being multiplied, as is often the case in prior artassemblies where the components are assembled together without a commonreference.

In the embodiment having the cover member with an axially projectinglip, the lip prevents damage to the funnel and plug if the apparatus isdropped. The relative positions of these components, and hence thegeometry of the first and second passages, is therefore protected.Additionally, the inner surface of the lip ensures that the apparatushas directionality, i.e. the atomized droplets can be directed towards achosen location. Although as discussed above, such directionality is notnecessary for the purpose of effective fluid mist fire protection.

Furthermore, droplets held against the inner surface of the lip are moreeasily atomized as they are subject to both the force of the secondfluid and the friction forces from the inner surface. However, it shouldbe understood that this first embodiment may alternatively have a lipwhich projects a relatively short distance, e.g. a few millimeters, orthe lip may be omitted from the first embodiment. In these instances,the atomizing process described above will take place substantiallyoutside of the mist-generating apparatus.

In the embodiment in which the cover member has no projecting lip, thereis no radial constriction of the fluid streams. Therefore the streamsare allowed to expand radially away from the longitudinal axis L of theapparatus at an earlier stage than they would if there was a lippresent. This creates a greater degree of turbulence in the secondfluid, which can enhance the atomization of the first fluid.Additionally, the resulting mist plume has a wider spread, which can bebeneficial in a situation where the apparatus is to fill a particularvolume with the mist as opposed to directing the plume towards aspecific location.

One or more of the fixing screws used in the assembly of the apparatusmay be replaced with an alternative mechanical fixture whereappropriate. Suitable examples include fixing bolts, clamps, or acombination thereof. One or more of the mechanical fixtures may be atamper proof or tamper evident fixture in order to either prevent orhighlight disassembly of the apparatus following installation.

Instead of using a threaded arrangement as in the alternativeembodiment, the adjustment of the axial position of the cover relativeto the base may alternatively be achieved by inserting shims between thetwo components and then tightening the two components together usingmechanical fixtures in the same manner as that of the first embodiment.

It should be recognized that the adapted features of the secondillustrated embodiment are not limited to being used in combination.These features may therefore be incorporated individually in the firstembodiment if desired. For example, an embodiment of the apparatushaving no lip present need not also be provided with the adjustmentarrangement for the cover member as well.

Whilst it is preferred that the apparatus is formed in the mannerdescribed from a base, funnel, plug and cover member, it should berecognized that the apparatus of the present invention is not limited tothe formation of the various fluid channels and passages using thesespecific components. The desired fluid channels and passages may becreated within the apparatus in an alternative manner to that described.For example, the channels and passages may be formed by drilling theapparatus, or else by casting the apparatus with the channels andpassages formed therein.

Although the apparatus is preferably manufactured from stainless steel,alternative materials sharing the same properties may also be usedinstead. The primary requirements of the material are resistance tocorrosion, chemicals and wear. It is also preferable that the materialis easily machined or formed, and relatively inexpensive. Possiblealternative materials include metals such as aluminum and brass, andmetal alloys such as tungsten. Plastics or ceramic materials having theaforementioned properties may also be used.

Again, whilst the preferred first fluid has been described as water, thepresent invention is not limited to this specific first fluid. Forexample, the first fluid could be a liquid fire retardant instead.Similarly, whilst the second fluid is preferably a gas, it is not to beconsidered as limited to the examples of gas given in the foregoingdisclosure. Other compressible fluids having similar properties to thegases disclosed may also be used without affecting the manner ofoperation of the present invention. The second fluid should preferablybe easily obtainable, relatively inexpensive and non-corrosive. It mayalso be beneficial to use a second fluid which has the additionalbenefits of being generated on site (e.g. via a compressor) and/or hasinerting benefits when used in fire suppression.

The inventors have provided methods, systems and devices for liquidmist-type fire protection that provides improved performance overpreviously known mist systems and technology. In particular, thepreferred methods, systems and devices provide for liquid mist fireprotection independent of the discharge device or atomizer locationrelative to any one of the floor space geometry and/or the hazard orfire location. In addition, the preferred system and methods provide forequal performance independent of the number of atomizers utilizedprovided that the total volume being discharged for the various systemconfigurations is substantially equal. Finally, the preferred systemshave demonstrated performance over known mist systems by (i) requiringless water and pressure consumption; and (ii) reducing the time toextinguishment over previously known mist systems.

While the present invention has been disclosed with reference to certainpreferred embodiments, numerous modifications, alterations, and changesto the described embodiments are possible without departing from thesphere and scope of the present invention, as described herein.

1. A method of mist fire protection for fixed equipment within asubstantially enclosed space having a ceiling, a plurality of walls soas to define a plurality of corners and an enclosure volume of at least130 cu. m. (4590 cu. ft.), the method comprising: disposing at least onemist generating device in the substantially enclosed space, thedisposing at least one mist generating device consisting of one of: (i)mounting at least two mist generating devices in the enclosed space,wherein the at least 130 cu. m. (4590 cu. ft.) (4590 cu. ft.) is atleast 260 cu. m. (9180 cu. ft.), the at least two mist generatingdevices being disposed in diagonally opposed corners so as to define aminimum spacing therebetween of about 3.4 m. (11 ft.); (ii) mounting theat least one mist generating device in a pendent configuration where theenclosure height ranges between about 3.0 m. (9.8 ft.) to about 8.0 m.(26.2 ft.) with a clearance from any wall of the enclosed space rangingfrom 0.3 m (1 ft.) to about 3.4 m. (11 ft.), (iii) mounting the at leastone mist generating device in a sidewall configuration where theenclosure height ranges between about 1.0 m. (3.3 ft.) to about 8.0 m.(26.2 ft.), the mounting being beneath the ceiling at a distance fromthe ceiling ranging from about 1.0 m. (3.3 ft.) to about one half theenclosure height and with a clearance of at least 1.0 m. (3.3 ft.) fromany of the plurality of corners of the enclosed space; (iv) mounting atleast two mist generating devices in a pendent configuration where theenclosure height ranges between about 3.0 m. (9.8 ft.) to about 8.0 m.(26.2 ft.) with a clearance from any of the plurality of walls of theenclosed space ranging from 0.3 m (1 ft.) to about 3.4 m. (11 ft.) andspaced from one another by a distance ranging from about 3.4 m. (11 ft.)to about 30.4 ft; and (v) mounting at least two mist generating devicesin a sidewall configuration where the sidewall enclosure height rangesbetween about 1.0 m. (3.3 ft.) to about 8.0 m. (26.2 ft.) beneath theceiling at a distance from the ceiling ranging from about 1.0 m. (3.3ft.) to about one half the ceiling enclosure height and with a clearanceof at least 1.0 m. (3.3 ft.) from any of the plurality of corners of theenclosed space such that the at least two mist generating devices eachdefine a center line of discharge having an unobstructed discharge pathwith a diameter of about 1.5 m. (5 ft.) from the device to an opposingwall of the plurality of walls, the device being mounted from theopposing wall at a distance ranging between about 3.8 m. (12.5 ft.) toabout 12.0 m. (39.3 ft.) with the center lines of discharge of the atleast two devices have a perpendicular spacing ranging between about 1.0m. (3.3 ft.) to about 4.6 m. (15 ft.); piping a self-contained fluidsupply source to the mist generating device, the piping includingcoupling an outlet of a liquid supply tank having a capacity of at least25 gallons to the mist generating device, the piping including couplingin parallel a gas supply having a bank of at least three pressurized11.3 cu. m. (400 cu. ft.) tanks with the liquid supply tank and the mistgenerating device; and interlocking an actuator to release the gas fromthe cylinders to the tank and the at least one mist generating device,the interlocking including coupling the actuator with a heat releasedetector disposed in the enclosed space, the heat detector beingresponsive to a fire in the enclosed space such that upon detection of afire, the heat detector signals the actuator to release the gas from thecylinders to pressurize the tank and delivery of the gas to the mistgenerating device.
 2. A kit to provide mist fire protection for fixedequipment within a substantially enclosed space having a ceiling, aplurality of walls so as to define a plurality of corners and anenclosure volume of at least 130 cu. m. (4590 cu. ft.), the kitcomprising: at least one mist generating device consisting of one of:(i) at least two mist generating devices to be mounted in the enclosedspace, wherein the at least 130 cu. m. (4590 cu. ft.) is at least 260cu. m. (9180 cu. ft.), the at least two mist generating devices to bedisposed in diagonally opposed corners so as to define a minimum spacingtherebetween of about 3.4 m. (11 ft.); (ii) at least one mist generatingdevice to be mounted in a pendent configuration in the enclosed spacewhere the enclosure height ranges between about 3.0 m. (9.8 ft.) toabout 5.0 m. (16.4 ft.) with a clearance from any wall of the enclosedspace ranging from 0.3 m (1 ft.) to about 3.4 m. (11 ft.); (iii) atleast one mist generating device to be mounted in a sidewallconfiguration in the enclosed space where the enclosure height rangesbetween about 1.0 m. (3.3 ft.) to about 5.0 m. (16.4 ft.), the at leastone mist generating device to be mounted being beneath the ceiling at adistance from the ceiling ranging from about 1.0 m. (3.3 ft.) to aboutone half the enclosure height and with a clearance of at least 1.0 m.(3.3 ft.) from any of the plurality of corners of the enclosed space;(iv) at least two mist generating devices to be mounted in a pendentconfiguration in the enclosed space where the enclosure height rangesbetween about 3.0 m. (9.8 ft.) to about 5.0 m. (16.4 ft.) with aclearance from any of the plurality of walls of the enclosed spaceranging from 0.3 m (1 ft.) to about 3.4 m. (11 ft.) and spaced from oneanother by a distance ranging from about 3.4 m. (11 ft.) to about 30.4ft; and (v) at least two mist generating devices to be mounted in asidewall configuration in the enclosed space where the sidewallenclosure height ranges between about 1.0 m. (3.3 ft.) to about 5.0 m.(16.4 ft.) beneath the ceiling at a distance from the ceiling rangingfrom about 1.0 m. (3.3 ft.) to about one half the ceiling enclosureheight and with a clearance of at least 1.0 m. (3.3 ft.) from any of theplurality of corners of the enclosed space such that the at least twomist generating devices each define a center line of discharge having anunobstructed discharge path with a diameter of about 1.5 m. (5 ft.) fromthe device to an opposing wall of the plurality of walls, the devicebeing mounted from the opposing wall at a distance ranging between about3.8 m. (12.5 ft.) to about 12.0 m. (39.3 ft.) with the center lines ofdischarge of the at least two devices have a perpendicular spacingranging between about 1.0 m. (3.3 ft.) to about 4.6 m. (15 ft.); the kitfurther comprising a self-contained fluid supply source, theself-contained fluid supply source including a liquid supply tank havinga capacity of about 25 gallons and a gas supply including a bank of atleast three (3) 11.3 cu. m. (400 cu. ft.) nitrogen gas cylinders coupledto a manifold having an outlet for connection to the at least oneatomizer, the manifold being connected to the liquid supply tank topressurize the tank, the tank including an outlet for connection to theat least one mist generating device; and an orifice for locating in-linebetween the outlet of the tank and the at least one atomizer to providea substantially constant flow of the liquid from the tank to the atleast one mist generating device. 3.-8. (canceled)
 9. A fire protectionsystem for addressing a fire with a mist, the system comprising: atleast one atomizing device disposed in an enclosed space having a volumeof at least 130 cu. m. (4590 cu. ft.), the at least one atomizing deviceincluding: a first fluid inlet and a second fluid inlet; and means foratomizing a first fluid with a second fluid; and a self-contained fluidsupply source including a liquid supply coupled to the first fluid inletfor discharge of liquid from the atomizing device as an annulus, thefluid supply further including a gas supply coupled to the second fluidinlet at a pressure ranging from about 2.1 bar (30 psi.) to about 24.1bar (350 psi.) for discharge from the atomizing device to mix with theliquid annulus in an optional chamber so as to form the mist to addressthe fire, the fluid supply further having a property that is selectedfrom the group consisting of: (i) the liquid supply pressurized by thegas supply, the liquid supply being coupled to the first fluid inlet toprovide the liquid to the inlet at a pressure of at least 0.5 bar (7psi.) for liquid flow through the first fluid passage; (ii) apressurized gas supply that includes a bank of at least three (3) 11.3cu. m. (400 cu. ft.) nitrogen gas cylinders, each cylinder being coupledto a piping manifold coupled to the second fluid outlet with a regulateddischarge pressure from the manifold of at least 6.9 bar (100 psi.), anda liquid supply that includes at least one ninety-five liter (95 L.)(twenty-five gallon (25 gal.)) tank of fire fighting liquid pressurizedby the gas supply discharge pressure, the tank being coupled to thefirst fluid inlet; and (iii) the liquid and gas being provided to thedevice in a liquid-to-gas mass flow ratio ranging from about 1:1 toabout 3:1; the mist further having a property that is selected from thegroup consisting of: (i) a majority of droplets having a diameterranging from 1 to 10 microns; (ii) a total liquid supply ranging betweenabout fifty-seven liters (57 L.) (fifteen gallons (15 gal.)) to aboutninety-five liters (95 L.) (twenty-five gallons (25 gal.)) for each 130cu. m. (4590 cu. ft.) of enclosed space; (iii) defines a totalextinguishing volume of less than about 8 gallons (8 gal.) for each 130cu. m. (4590 cu. ft.) of enclosed space; and (iv) an extinguishment timeranging from about 780 seconds to about 80 seconds for normalized sizedfires ranging between about 1 kW/cu. m. to about 8 kW/cu. m. 10.-15.(canceled)
 16. A method of total flooding mist fire protection for anenclosed space, the method comprising: discharging a volume of mist fromat least one atomizing device into the enclosed space, distributing thevolume of mist so as to define a density for each unit of volumetricspace in the room capable of extinguishing a fire located anywhere inthe room, and providing a self-contained fluid supply source, the selfcontained fluid supply source including: a liquid supply coupled to theat least one atomizing device for discharge of liquid from the device asan annulus; and a gas supply coupled to the at least one atomizingdevice at a pressure ranging from about 2.1 bar (30 psi.) to about 24.1bar (350 psi.) for discharge from the device to mix with the liquidannulus so as to form the mist, the providing further being selectedfrom the group consisting of: (i) the liquid supply pressurized by thegas supply, the liquid supply being coupled to the first fluid inlet toprovide the liquid to the inlet at a pressure of at least 0.5 bar (7psi.) for liquid flow through the first fluid passage: (ii) apressurized gas supply that includes a bank of at least three (3) 11.3cu. m. (400 cu. ft.) nitrogen gas cylinders, each cylinder being coupledto a piping manifold coupled to the second fluid outlet with a regulateddischarge pressure from the manifold of at least 6.9 bar (100 psi.), anda liquid supply that includes at least one ninety-five liter (95 L.)(twenty-five gallon (25 gal.)) tank of fire fighting liquid pressurizedby the gas supply discharge pressure, the tank being coupled to thefirst fluid inlet; and (iii) the liquid and gas being provided to thedevice in a liquid-to-gas mass flow ratio ranging from about 1:1 toabout 3:1.
 17. The method of claim 16, further comprising generating themist by means of one of the parameters selected from the groupconsisting of: (i) a majority of droplets having a diameter ranging from1 to 10 microns; (ii) a total liquid supply ranging between aboutfifty-seven liters (57 L.) (fifteen gallons (15 gal.)) to aboutninety-five liters (95 L.) (twenty-five gallons (25 gal.)) for each 130cu. m. (4590 cu. ft.) of enclosed space; (iii) defines a totalextinguishing volume of less than about 8 gallons (8 gal.) for each 130cu. m. (4590 cu. ft.) of enclosed space; and (iv) an extinguishment timeranging from about 780 seconds to about 80 seconds for normalized sizedfires ranging between about 1 kW/cu. m. to about 8 kW/cu. m.
 18. Themethod of claim 16, wherein the at least one atomizer comprises: a firstfluid passage having a first fluid inlet and a first fluid outletdisposed about a longitudinal axis of the apparatus, the first fluidpassage defining a working nozzle: a second fluid passage having asecond fluid inlet and a second fluid outlet, the second fluid passagedisposed about the longitudinal axis of the apparatus and co-axial withthe first fluid passage, the second fluid passage defining a transportnozzle; a solid protrusion disposed in the second fluid passage so thatthe transport nozzle defines a divergent flow pattern with respect tothe longitudinal axis; and a chamber in communication with the workingnozzle and transport nozzle.
 19. The method of claim 16, furthercomprising generating liquid droplets forming the liquid mist, wherein amajority of the droplets have a diameter ranging from 1 to 5 microns.20. The method of claim 16, further comprising generating turbulence inthe volume so as to induce air currents capable of transporting anddispersing the liquid mist.
 21. The method of claim 16, wherein the gasis discharged at a supersonic speed.
 22. The method of claim 16, whereinthe discharging includes defining a total liquid volume to extinguish anormalized fire size measured in kilowatts per cubic meter (kW/m.³), thetotal extinguishing volume ranging respectively from about from 0.57liters per cubic meter (0.57 liters/cu. m.) (0.0042 gallons per cubicfoot (0.0042 gal./cu. ft.)) to 0.057 liters per cubic meter (0.057liters/cu. m.) (0.00042 gallons per cubic foot (0.00042 gal./cu. ft.)for a normalized range of fire sizes ranging from about one (1 kW/m³) toabout eight (8 kW/m.³).
 23. The method of claim 22, wherein thedischarging is a function of the space being protected having a volumesize of about 260 cubic meter (cu. m.), wherein further the liquid mistdefines an extinguishment volume of about four gallons (4 gal.) ofliquid to about forty gallons (40 gal.).
 24. The method of claim 16,wherein the discharging a liquid mist extinguishes a fire and defines arange of extinguishing times ranging respectively from about 780 secondsto about 80 seconds for normalized fire sizes ranging between about (1kW/cu. m.) to about (8 kW/cu. m.).
 25. The method of claim 24, furtherdefining a range of extinguishing times from about 500 seconds to about80 seconds for normalized fire sizes ranging between about (1 kW/cu. m.)to about (8 kW/cu. m.).
 26. The method of claim 25, further defining arange of extinguishing times from about, 420 seconds to about 80 secondsfor normalized fire sizes ranging between about (1 kW/cu. m.) to about(8 kW/cu. m.). 27.-71. (canceled)